diff --git a/substrate/core/basic-authorship/src/basic_authorship.rs b/substrate/core/basic-authorship/src/basic_authorship.rs
index 87d0b8f92b..166a89447e 100644
--- a/substrate/core/basic-authorship/src/basic_authorship.rs
+++ b/substrate/core/basic-authorship/src/basic_authorship.rs
@@ -56,7 +56,7 @@ pub trait AuthoringApi: Send + Sync + ProvideRuntimeApi where
 
 	/// Build a block on top of the given block, with inherent extrinsics and
 	/// inherent digests pre-pushed.
-	fn build_block<F: FnMut(&mut BlockBuilder<Self::Block>) -> ()>(
+	fn build_block<F: FnMut(&mut dyn BlockBuilder<Self::Block>) -> ()>(
 		&self,
 		at: &BlockId<Self::Block>,
 		inherent_data: InherentData,
@@ -91,7 +91,7 @@ impl<B, E, Block, RA> AuthoringApi for SubstrateClient<B, E, Block, RA> where
 	type Block = Block;
 	type Error = client::error::Error;
 
-	fn build_block<F: FnMut(&mut BlockBuilder<Self::Block>) -> ()>(
+	fn build_block<F: FnMut(&mut dyn BlockBuilder<Self::Block>) -> ()>(
 		&self,
 		at: &BlockId<Self::Block>,
 		inherent_data: InherentData,
@@ -162,7 +162,7 @@ pub struct Proposer<Block: BlockT, C, A: txpool::ChainApi> {
 	parent_id: BlockId<Block>,
 	parent_number: <<Block as BlockT>::Header as HeaderT>::Number,
 	transaction_pool: Arc<TransactionPool<A>>,
-	now: Box<Fn() -> time::Instant>,
+	now: Box<dyn Fn() -> time::Instant>,
 }
 
 impl<Block, C, A> consensus_common::Proposer<<C as AuthoringApi>::Block> for Proposer<Block, C, A> where
diff --git a/substrate/core/cli/src/lib.rs b/substrate/core/cli/src/lib.rs
index 3619e6491a..c14c962591 100644
--- a/substrate/core/cli/src/lib.rs
+++ b/substrate/core/cli/src/lib.rs
@@ -617,7 +617,7 @@ where
 	let to = cli.to;
 	let json = cli.json;
 
-	let file: Box<Write> = match cli.output {
+	let file: Box<dyn Write> = match cli.output {
 		Some(filename) => Box::new(File::create(filename)?),
 		None => Box::new(stdout()),
 	};
@@ -640,7 +640,7 @@ where
 {
 	let config = create_config_with_db_path::<F, _>(spec_factory, &cli.shared_params, version)?;
 
-	let file: Box<Read> = match cli.input {
+	let file: Box<dyn Read> = match cli.input {
 		Some(filename) => Box::new(File::open(filename)?),
 		None => Box::new(stdin()),
 	};
diff --git a/substrate/core/cli/src/params.rs b/substrate/core/cli/src/params.rs
index 7439cc02c0..0cdc633188 100644
--- a/substrate/core/cli/src/params.rs
+++ b/substrate/core/cli/src/params.rs
@@ -476,7 +476,7 @@ impl Keyring {
 }
 
 /// Default to verbosity level 0, if none is provided.
-fn parse_telemetry_endpoints(s: &str) -> Result<(String, u8), Box<std::error::Error>> {
+fn parse_telemetry_endpoints(s: &str) -> Result<(String, u8), Box<dyn std::error::Error>> {
 	let pos = s.find(' ');
 	match pos {
 		None => {
@@ -512,7 +512,7 @@ impl From<Cors> for Option<Vec<String>> {
 }
 
 /// Parse cors origins
-fn parse_cors(s: &str) -> Result<Cors, Box<std::error::Error>> {
+fn parse_cors(s: &str) -> Result<Cors, Box<dyn std::error::Error>> {
 	let mut is_all = false;
 	let mut origins = Vec::new();
 	for part in s.split(',') {
diff --git a/substrate/core/client/db/src/cache/list_storage.rs b/substrate/core/client/db/src/cache/list_storage.rs
index 6271f892bc..af0b74066c 100644
--- a/substrate/core/client/db/src/cache/list_storage.rs
+++ b/substrate/core/client/db/src/cache/list_storage.rs
@@ -97,19 +97,19 @@ pub struct DbColumns {
 pub struct DbStorage {
 	name: Vec<u8>,
 	meta_key: Vec<u8>,
-	db: Arc<KeyValueDB>,
+	db: Arc<dyn KeyValueDB>,
 	columns: DbColumns,
 }
 
 impl DbStorage {
 	/// Create new database-backed list cache storage.
-	pub fn new(name: Vec<u8>, db: Arc<KeyValueDB>, columns: DbColumns) -> Self {
+	pub fn new(name: Vec<u8>, db: Arc<dyn KeyValueDB>, columns: DbColumns) -> Self {
 		let meta_key = meta::key(&name);
 		DbStorage { name, meta_key, db, columns }
 	}
 
 	/// Get reference to the database.
-	pub fn db(&self) -> &Arc<KeyValueDB> { &self.db }
+	pub fn db(&self) -> &Arc<dyn KeyValueDB> { &self.db }
 
 	/// Get reference to the database columns.
 	pub fn columns(&self) -> &DbColumns { &self.columns }
diff --git a/substrate/core/client/db/src/cache/mod.rs b/substrate/core/client/db/src/cache/mod.rs
index d79b01ab6b..64d3c4a25e 100644
--- a/substrate/core/client/db/src/cache/mod.rs
+++ b/substrate/core/client/db/src/cache/mod.rs
@@ -77,7 +77,7 @@ impl<T> CacheItemT for T where T: Clone + Decode + Encode + PartialEq {}
 /// Database-backed blockchain data cache.
 pub struct DbCache<Block: BlockT> {
 	cache_at: HashMap<CacheKeyId, ListCache<Block, Vec<u8>, self::list_storage::DbStorage>>,
-	db: Arc<KeyValueDB>,
+	db: Arc<dyn KeyValueDB>,
 	key_lookup_column: Option<u32>,
 	header_column: Option<u32>,
 	authorities_column: Option<u32>,
@@ -88,7 +88,7 @@ pub struct DbCache<Block: BlockT> {
 impl<Block: BlockT> DbCache<Block> {
 	/// Create new cache.
 	pub fn new(
-		db: Arc<KeyValueDB>,
+		db: Arc<dyn KeyValueDB>,
 		key_lookup_column: Option<u32>,
 		header_column: Option<u32>,
 		authorities_column: Option<u32>,
@@ -150,7 +150,7 @@ impl<Block: BlockT> DbCache<Block> {
 fn get_cache_helper<'a, Block: BlockT>(
 	cache_at: &'a mut HashMap<CacheKeyId, ListCache<Block, Vec<u8>, self::list_storage::DbStorage>>,
 	name: CacheKeyId,
-	db: &Arc<KeyValueDB>,
+	db: &Arc<dyn KeyValueDB>,
 	key_lookup: Option<u32>,
 	header: Option<u32>,
 	cache: Option<u32>,
diff --git a/substrate/core/client/db/src/lib.rs b/substrate/core/client/db/src/lib.rs
index a253cc6783..302cdfd083 100644
--- a/substrate/core/client/db/src/lib.rs
+++ b/substrate/core/client/db/src/lib.rs
@@ -70,7 +70,7 @@ const CANONICALIZATION_DELAY: u64 = 4096;
 const MIN_BLOCKS_TO_KEEP_CHANGES_TRIES_FOR: u32 = 32768;
 
 /// DB-backed patricia trie state, transaction type is an overlay of changes to commit.
-pub type DbState = state_machine::TrieBackend<Arc<state_machine::Storage<Blake2Hasher>>, Blake2Hasher>;
+pub type DbState = state_machine::TrieBackend<Arc<dyn state_machine::Storage<Blake2Hasher>>, Blake2Hasher>;
 
 pub struct RefTrackingState<Block: BlockT> {
 	state: DbState,
@@ -213,7 +213,7 @@ struct PendingBlock<Block: BlockT> {
 }
 
 // wrapper that implements trait required for state_db
-struct StateMetaDb<'a>(&'a KeyValueDB);
+struct StateMetaDb<'a>(&'a dyn KeyValueDB);
 
 impl<'a> state_db::MetaDb for StateMetaDb<'a> {
 	type Error = io::Error;
@@ -225,13 +225,13 @@ impl<'a> state_db::MetaDb for StateMetaDb<'a> {
 
 /// Block database
 pub struct BlockchainDb<Block: BlockT> {
-	db: Arc<KeyValueDB>,
+	db: Arc<dyn KeyValueDB>,
 	meta: Arc<RwLock<Meta<NumberFor<Block>, Block::Hash>>>,
 	leaves: RwLock<LeafSet<Block::Hash, NumberFor<Block>>>,
 }
 
 impl<Block: BlockT> BlockchainDb<Block> {
-	fn new(db: Arc<KeyValueDB>) -> Result<Self, client::error::Error> {
+	fn new(db: Arc<dyn KeyValueDB>) -> Result<Self, client::error::Error> {
 		let meta = read_meta::<Block>(&*db, columns::META, columns::HEADER)?;
 		let leaves = LeafSet::read_from_db(&*db, columns::META, meta_keys::LEAF_PREFIX)?;
 		Ok(BlockchainDb {
@@ -340,7 +340,7 @@ impl<Block: BlockT> client::blockchain::Backend<Block> for BlockchainDb<Block> {
 		Ok(self.meta.read().finalized_hash.clone())
 	}
 
-	fn cache(&self) -> Option<Arc<client::blockchain::Cache<Block>>> {
+	fn cache(&self) -> Option<Arc<dyn client::blockchain::Cache<Block>>> {
 		None
 	}
 
@@ -354,7 +354,7 @@ impl<Block: BlockT> client::blockchain::Backend<Block> for BlockchainDb<Block> {
 }
 
 impl<Block: BlockT> client::blockchain::ProvideCache<Block> for BlockchainDb<Block> {
-	fn cache(&self) -> Option<Arc<client::blockchain::Cache<Block>>> {
+	fn cache(&self) -> Option<Arc<dyn client::blockchain::Cache<Block>>> {
 		None
 	}
 }
@@ -473,7 +473,7 @@ where Block: BlockT<Hash=H256>,
 }
 
 struct StorageDb<Block: BlockT> {
-	pub db: Arc<KeyValueDB>,
+	pub db: Arc<dyn KeyValueDB>,
 	pub state_db: StateDb<Block::Hash, Vec<u8>>,
 }
 
@@ -512,7 +512,7 @@ impl state_machine::Storage<Blake2Hasher> for DbGenesisStorage {
 }
 
 pub struct DbChangesTrieStorage<Block: BlockT> {
-	db: Arc<KeyValueDB>,
+	db: Arc<dyn KeyValueDB>,
 	meta: Arc<RwLock<Meta<NumberFor<Block>, Block::Hash>>>,
 	min_blocks_to_keep: Option<u32>,
 	_phantom: ::std::marker::PhantomData<Block>,
@@ -693,7 +693,12 @@ impl<Block: BlockT<Hash=H256>> Backend<Block> {
 		).expect("failed to create test-db")
 	}
 
-	fn from_kvdb(db: Arc<KeyValueDB>, pruning: PruningMode, canonicalization_delay: u64, state_cache_size: usize) -> Result<Self, client::error::Error> {
+	fn from_kvdb(
+		db: Arc<dyn KeyValueDB>,
+		pruning: PruningMode,
+		canonicalization_delay: u64,
+		state_cache_size: usize
+	) -> Result<Self, client::error::Error> {
 		let is_archive_pruning = pruning.is_archive();
 		let blockchain = BlockchainDb::new(db.clone())?;
 		let meta = blockchain.meta.clone();
diff --git a/substrate/core/client/db/src/light.rs b/substrate/core/client/db/src/light.rs
index e0f2153a13..b3398bfdff 100644
--- a/substrate/core/client/db/src/light.rs
+++ b/substrate/core/client/db/src/light.rs
@@ -59,7 +59,7 @@ const CHANGES_TRIE_CHT_PREFIX: u8 = 1;
 /// Light blockchain storage. Stores most recent headers + CHTs for older headers.
 /// Locks order: meta, leaves, cache.
 pub struct LightStorage<Block: BlockT> {
-	db: Arc<KeyValueDB>,
+	db: Arc<dyn KeyValueDB>,
 	meta: RwLock<Meta<NumberFor<Block>, Block::Hash>>,
 	leaves: RwLock<LeafSet<Block::Hash, NumberFor<Block>>>,
 	cache: Arc<DbCacheSync<Block>>,
@@ -96,7 +96,7 @@ impl<Block> LightStorage<Block>
 		Self::from_kvdb(db as Arc<_>).expect("failed to create test-db")
 	}
 
-	fn from_kvdb(db: Arc<KeyValueDB>) -> ClientResult<Self> {
+	fn from_kvdb(db: Arc<dyn KeyValueDB>) -> ClientResult<Self> {
 		let meta = read_meta::<Block>(&*db, columns::META, columns::HEADER)?;
 		let leaves = LeafSet::read_from_db(&*db, columns::META, meta_keys::LEAF_PREFIX)?;
 		let cache = DbCache::new(
@@ -557,7 +557,7 @@ impl<Block> LightBlockchainStorage<Block> for LightStorage<Block>
 		Ok(self.meta.read().finalized_hash.clone())
 	}
 
-	fn cache(&self) -> Option<Arc<BlockchainCache<Block>>> {
+	fn cache(&self) -> Option<Arc<dyn BlockchainCache<Block>>> {
 		Some(self.cache.clone())
 	}
 }
@@ -888,7 +888,7 @@ pub(crate) mod tests {
 			map
 		}
 
-		fn get_authorities(cache: &BlockchainCache<Block>, at: BlockId<Block>) -> Option<Vec<AuthorityId>> {
+		fn get_authorities(cache: &dyn BlockchainCache<Block>, at: BlockId<Block>) -> Option<Vec<AuthorityId>> {
 			cache.get_at(&well_known_cache_keys::AUTHORITIES, &at).and_then(|val| Decode::decode(&mut &val[..]))
 		}
 
diff --git a/substrate/core/client/db/src/utils.rs b/substrate/core/client/db/src/utils.rs
index 846bf05f3c..bd7cf660ea 100644
--- a/substrate/core/client/db/src/utils.rs
+++ b/substrate/core/client/db/src/utils.rs
@@ -17,9 +17,7 @@
 //! Db-based backend utility structures and functions, used by both
 //! full and light storages.
 
-use std::sync::Arc;
-use std::io;
-use std::convert::TryInto;
+use std::{io, convert::TryInto, sync::Arc};
 
 use kvdb::{KeyValueDB, DBTransaction};
 #[cfg(feature = "kvdb-rocksdb")]
@@ -171,7 +169,7 @@ pub fn insert_hash_to_key_mapping<N: TryInto<u32>, H: AsRef<[u8]> + Clone>(
 /// block lookup key is the DB-key header, block and justification are stored under.
 /// looks up lookup key by hash from DB as necessary.
 pub fn block_id_to_lookup_key<Block>(
-	db: &KeyValueDB,
+	db: &dyn KeyValueDB,
 	key_lookup_col: Option<u32>,
 	id: BlockId<Block>
 ) -> Result<Option<Vec<u8>>, client::error::Error> where
@@ -197,7 +195,11 @@ pub fn db_err(err: io::Error) -> client::error::Error {
 
 /// Open RocksDB database.
 #[cfg(feature = "kvdb-rocksdb")]
-pub fn open_database(config: &DatabaseSettings, col_meta: Option<u32>, db_type: &str) -> client::error::Result<Arc<KeyValueDB>> {
+pub fn open_database(
+	config: &DatabaseSettings,
+	col_meta: Option<u32>,
+	db_type: &str
+) -> client::error::Result<Arc<dyn KeyValueDB>> {
 	let mut db_config = DatabaseConfig::with_columns(Some(NUM_COLUMNS));
 	db_config.memory_budget = config.cache_size;
 	let path = config.path.to_str().ok_or_else(|| client::error::Error::Backend("Invalid database path".into()))?;
@@ -222,7 +224,12 @@ pub fn open_database(config: &DatabaseSettings, col_meta: Option<u32>, db_type:
 }
 
 /// Read database column entry for the given block.
-pub fn read_db<Block>(db: &KeyValueDB, col_index: Option<u32>, col: Option<u32>, id: BlockId<Block>) -> client::error::Result<Option<DBValue>>
+pub fn read_db<Block>(
+	db: &dyn KeyValueDB,
+	col_index: Option<u32>,
+	col: Option<u32>,
+	id: BlockId<Block>
+) -> client::error::Result<Option<DBValue>>
 	where
 		Block: BlockT,
 {
@@ -234,7 +241,7 @@ pub fn read_db<Block>(db: &KeyValueDB, col_index: Option<u32>, col: Option<u32>,
 
 /// Read a header from the database.
 pub fn read_header<Block: BlockT>(
-	db: &KeyValueDB,
+	db: &dyn KeyValueDB,
 	col_index: Option<u32>,
 	col: Option<u32>,
 	id: BlockId<Block>,
@@ -252,7 +259,7 @@ pub fn read_header<Block: BlockT>(
 
 /// Required header from the database.
 pub fn require_header<Block: BlockT>(
-	db: &KeyValueDB,
+	db: &dyn KeyValueDB,
 	col_index: Option<u32>,
 	col: Option<u32>,
 	id: BlockId<Block>,
@@ -262,7 +269,7 @@ pub fn require_header<Block: BlockT>(
 }
 
 /// Read meta from the database.
-pub fn read_meta<Block>(db: &KeyValueDB, col_meta: Option<u32>, col_header: Option<u32>) -> Result<
+pub fn read_meta<Block>(db: &dyn KeyValueDB, col_meta: Option<u32>, col_header: Option<u32>) -> Result<
 	Meta<<<Block as BlockT>::Header as HeaderT>::Number, Block::Hash>,
 	client::error::Error,
 >
diff --git a/substrate/core/client/src/blockchain.rs b/substrate/core/client/src/blockchain.rs
index 05210fc9ad..b07e26396e 100644
--- a/substrate/core/client/src/blockchain.rs
+++ b/substrate/core/client/src/blockchain.rs
@@ -81,7 +81,7 @@ pub trait Backend<Block: BlockT>: HeaderBackend<Block> {
 	/// Get last finalized block hash.
 	fn last_finalized(&self) -> Result<Block::Hash>;
 	/// Returns data cache reference, if it is enabled on this backend.
-	fn cache(&self) -> Option<Arc<Cache<Block>>>;
+	fn cache(&self) -> Option<Arc<dyn Cache<Block>>>;
 
 	/// Returns hashes of all blocks that are leaves of the block tree.
 	/// in other words, that have no children, are chain heads.
@@ -95,7 +95,7 @@ pub trait Backend<Block: BlockT>: HeaderBackend<Block> {
 /// Provides access to the optional cache.
 pub trait ProvideCache<Block: BlockT> {
 	/// Returns data cache reference, if it is enabled on this backend.
-	fn cache(&self) -> Option<Arc<Cache<Block>>>;
+	fn cache(&self) -> Option<Arc<dyn Cache<Block>>>;
 }
 
 /// Blockchain optional data cache.
diff --git a/substrate/core/client/src/call_executor.rs b/substrate/core/client/src/call_executor.rs
index bb59be44c3..f956f27b50 100644
--- a/substrate/core/client/src/call_executor.rs
+++ b/substrate/core/client/src/call_executor.rs
@@ -125,7 +125,7 @@ where
 		let trie_state = state.as_trie_backend()
 			.ok_or_else(||
 				Box::new(state_machine::ExecutionError::UnableToGenerateProof)
-					as Box<state_machine::Error>
+					as Box<dyn state_machine::Error>
 			)?;
 		self.prove_at_trie_state(trie_state, overlay, method, call_data)
 	}
@@ -246,7 +246,7 @@ where
 				let trie_state = state.as_trie_backend()
 					.ok_or_else(||
 						Box::new(state_machine::ExecutionError::UnableToGenerateProof)
-							as Box<state_machine::Error>
+							as Box<dyn state_machine::Error>
 					)?;
 
 				let backend = state_machine::ProvingBackend::new_with_recorder(
diff --git a/substrate/core/client/src/children.rs b/substrate/core/client/src/children.rs
index 3a9f0a6bea..4423ad8939 100644
--- a/substrate/core/client/src/children.rs
+++ b/substrate/core/client/src/children.rs
@@ -26,7 +26,7 @@ use std::hash::Hash;
 pub fn read_children<
 	K: Eq + Hash + Clone + Encode + Decode,
 	V: Eq + Hash + Clone + Encode + Decode,
->(db: &KeyValueDB, column: Option<u32>, prefix: &[u8], parent_hash: K) -> error::Result<Vec<V>> {
+>(db: &dyn KeyValueDB, column: Option<u32>, prefix: &[u8], parent_hash: K) -> error::Result<Vec<V>> {
 	let mut buf = prefix.to_vec();
 	parent_hash.using_encoded(|s| buf.extend(s));
 
@@ -116,6 +116,6 @@ mod tests {
 		let r2: Vec<u32> = read_children(&db, None, PREFIX, 1_2).unwrap();
 
 		assert_eq!(r1, vec![1_3, 1_5]);
-		assert_eq!(r2.len(), 0);		
+		assert_eq!(r2.len(), 0);
 	}
 }
diff --git a/substrate/core/client/src/client.rs b/substrate/core/client/src/client.rs
index 0d8f8aa548..f4183e4958 100644
--- a/substrate/core/client/src/client.rs
+++ b/substrate/core/client/src/client.rs
@@ -564,7 +564,7 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 		cht_size: NumberFor<Block>,
 	) -> error::Result<ChangesProof<Block::Header>> {
 		struct AccessedRootsRecorder<'a, Block: BlockT> {
-			storage: &'a ChangesTrieStorage<Blake2Hasher, NumberFor<Block>>,
+			storage: &'a dyn ChangesTrieStorage<Blake2Hasher, NumberFor<Block>>,
 			min: NumberFor<Block>,
 			required_roots_proofs: Mutex<BTreeMap<NumberFor<Block>, H256>>,
 		};
@@ -695,7 +695,7 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 
 	/// Create a new block, built on the head of the chain.
 	pub fn new_block(
-		&self, 
+		&self,
 		inherent_digests: DigestFor<Block>,
 	) -> error::Result<block_builder::BlockBuilder<Block, Self>> where
 		E: Clone + Send + Sync,
@@ -708,8 +708,8 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 
 	/// Create a new block, built on top of `parent`.
 	pub fn new_block_at(
-		&self, 
-		parent: &BlockId<Block>, 
+		&self,
+		parent: &BlockId<Block>,
 		inherent_digests: DigestFor<Block>,
 	) -> error::Result<block_builder::BlockBuilder<Block, Self>> where
 		E: Clone + Send + Sync,
@@ -726,8 +726,8 @@ impl<B, E, Block, RA> Client<B, E, Block, RA> where
 	/// These recorded trie nodes can be used by a third party to proof the
 	/// output of this block builder without having access to the full storage.
 	pub fn new_block_at_with_proof_recording(
-		&self, 
-		parent: &BlockId<Block>, 
+		&self,
+		parent: &BlockId<Block>,
 		inherent_digests: DigestFor<Block>,
 	) -> error::Result<block_builder::BlockBuilder<Block, Self>> where
 		E: Clone + Send + Sync,
@@ -1319,7 +1319,7 @@ impl<B, E, Block, RA> ProvideCache<Block> for Client<B, E, Block, RA> where
 	B: backend::Backend<Block, Blake2Hasher>,
 	Block: BlockT<Hash=H256>,
 {
-	fn cache(&self) -> Option<Arc<Cache<Block>>> {
+	fn cache(&self) -> Option<Arc<dyn Cache<Block>>> {
 		self.backend.blockchain().cache()
 	}
 }
diff --git a/substrate/core/client/src/error.rs b/substrate/core/client/src/error.rs
index bad279f2e4..b807d5e11c 100644
--- a/substrate/core/client/src/error.rs
+++ b/substrate/core/client/src/error.rs
@@ -42,7 +42,7 @@ pub enum Error {
 	ApplyExtrinsicFailed(ApplyError),
 	/// Execution error.
 	#[display(fmt = "Execution: {}", _0)]
-	Execution(Box<state_machine::Error>),
+	Execution(Box<dyn state_machine::Error>),
 	/// Blockchain error.
 	#[display(fmt = "Blockchain: {}", _0)]
 	Blockchain(Box<Error>),
@@ -100,7 +100,7 @@ pub enum Error {
 }
 
 impl error::Error for Error {
-	fn source(&self) -> Option<&(error::Error + 'static)> {
+	fn source(&self) -> Option<&(dyn error::Error + 'static)> {
 		match self {
 			Error::Consensus(e) => Some(e),
 			Error::Blockchain(e) => Some(e),
@@ -128,7 +128,7 @@ impl Error {
 	}
 
 	/// Chain a state error.
-	pub fn from_state(e: Box<state_machine::Error + Send>) -> Self {
+	pub fn from_state(e: Box<dyn state_machine::Error + Send>) -> Self {
 		Error::Execution(e)
 	}
 }
diff --git a/substrate/core/client/src/in_mem.rs b/substrate/core/client/src/in_mem.rs
index 6c11d0ed57..92d04230dd 100644
--- a/substrate/core/client/src/in_mem.rs
+++ b/substrate/core/client/src/in_mem.rs
@@ -343,7 +343,7 @@ impl<Block: BlockT> blockchain::Backend<Block> for Blockchain<Block> {
 		Ok(self.storage.read().finalized_hash.clone())
 	}
 
-	fn cache(&self) -> Option<Arc<blockchain::Cache<Block>>> {
+	fn cache(&self) -> Option<Arc<dyn blockchain::Cache<Block>>> {
 		None
 	}
 
@@ -357,7 +357,7 @@ impl<Block: BlockT> blockchain::Backend<Block> for Blockchain<Block> {
 }
 
 impl<Block: BlockT> blockchain::ProvideCache<Block> for Blockchain<Block> {
-	fn cache(&self) -> Option<Arc<blockchain::Cache<Block>>> {
+	fn cache(&self) -> Option<Arc<dyn blockchain::Cache<Block>>> {
 		None
 	}
 }
@@ -433,7 +433,7 @@ impl<Block: BlockT> light::blockchain::Storage<Block> for Blockchain<Block>
 			.ok_or_else(|| error::Error::Backend(format!("Changes trie CHT for block {} not exists", block)))
 	}
 
-	fn cache(&self) -> Option<Arc<blockchain::Cache<Block>>> {
+	fn cache(&self) -> Option<Arc<dyn blockchain::Cache<Block>>> {
 		None
 	}
 }
diff --git a/substrate/core/client/src/leaves.rs b/substrate/core/client/src/leaves.rs
index 144237f777..b0e49ead80 100644
--- a/substrate/core/client/src/leaves.rs
+++ b/substrate/core/client/src/leaves.rs
@@ -77,7 +77,7 @@ impl<H, N> LeafSet<H, N> where
 	}
 
 	/// Read the leaf list from the DB, using given prefix for keys.
-	pub fn read_from_db(db: &KeyValueDB, column: Option<u32>, prefix: &[u8]) -> error::Result<Self> {
+	pub fn read_from_db(db: &dyn KeyValueDB, column: Option<u32>, prefix: &[u8]) -> error::Result<Self> {
 		let mut storage = BTreeMap::new();
 
 		for (key, value) in db.iter_from_prefix(column, prefix) {
diff --git a/substrate/core/client/src/light/blockchain.rs b/substrate/core/client/src/light/blockchain.rs
index 62c13db5a4..e3d9c55a6a 100644
--- a/substrate/core/client/src/light/blockchain.rs
+++ b/substrate/core/client/src/light/blockchain.rs
@@ -70,7 +70,7 @@ pub trait Storage<Block: BlockT>: AuxStore + BlockchainHeaderBackend<Block> {
 	) -> ClientResult<Block::Hash>;
 
 	/// Get storage cache.
-	fn cache(&self) -> Option<Arc<BlockchainCache<Block>>>;
+	fn cache(&self) -> Option<Arc<dyn BlockchainCache<Block>>>;
 }
 
 /// Light client blockchain.
@@ -175,7 +175,7 @@ impl<S, F, Block> BlockchainBackend<Block> for Blockchain<S, F> where Block: Blo
 		self.storage.last_finalized()
 	}
 
-	fn cache(&self) -> Option<Arc<BlockchainCache<Block>>> {
+	fn cache(&self) -> Option<Arc<dyn BlockchainCache<Block>>> {
 		self.storage.cache()
 	}
 
@@ -189,7 +189,7 @@ impl<S, F, Block> BlockchainBackend<Block> for Blockchain<S, F> where Block: Blo
 }
 
 impl<S: Storage<Block>, F, Block: BlockT> ProvideCache<Block> for Blockchain<S, F> {
-	fn cache(&self) -> Option<Arc<BlockchainCache<Block>>> {
+	fn cache(&self) -> Option<Arc<dyn BlockchainCache<Block>>> {
 		self.storage.cache()
 	}
 }
@@ -303,7 +303,7 @@ pub mod tests {
 				).into())
 		}
 
-		fn cache(&self) -> Option<Arc<BlockchainCache<Block>>> {
+		fn cache(&self) -> Option<Arc<dyn BlockchainCache<Block>>> {
 			None
 		}
 	}
diff --git a/substrate/core/client/src/light/call_executor.rs b/substrate/core/client/src/light/call_executor.rs
index 5b6d1b3a29..a6b381a8b1 100644
--- a/substrate/core/client/src/light/call_executor.rs
+++ b/substrate/core/client/src/light/call_executor.rs
@@ -400,7 +400,7 @@ pub fn prove_execution<Block, S, E>(
 		E: CallExecutor<Block, Blake2Hasher>,
 {
 	let trie_state = state.as_trie_backend()
-		.ok_or_else(|| Box::new(state_machine::ExecutionError::UnableToGenerateProof) as Box<state_machine::Error>)?;
+		.ok_or_else(|| Box::new(state_machine::ExecutionError::UnableToGenerateProof) as Box<dyn state_machine::Error>)?;
 
 	// prepare execution environment + record preparation proof
 	let mut changes = Default::default();
diff --git a/substrate/core/client/src/light/fetcher.rs b/substrate/core/client/src/light/fetcher.rs
index f25a2acd30..985aa5bdaa 100644
--- a/substrate/core/client/src/light/fetcher.rs
+++ b/substrate/core/client/src/light/fetcher.rs
@@ -620,7 +620,7 @@ pub mod tests {
 	#[test]
 	fn storage_read_proof_is_generated_and_checked() {
 		let (local_checker, remote_block_header, remote_read_proof, authorities_len) = prepare_for_read_proof_check();
-		assert_eq!((&local_checker as &FetchChecker<Block>).check_read_proof(&RemoteReadRequest::<Header> {
+		assert_eq!((&local_checker as &dyn FetchChecker<Block>).check_read_proof(&RemoteReadRequest::<Header> {
 			block: remote_block_header.hash(),
 			header: remote_block_header,
 			key: well_known_keys::AUTHORITY_COUNT.to_vec(),
@@ -631,7 +631,7 @@ pub mod tests {
 	#[test]
 	fn header_proof_is_generated_and_checked() {
 		let (local_checker, local_cht_root, remote_block_header, remote_header_proof) = prepare_for_header_proof_check(true);
-		assert_eq!((&local_checker as &FetchChecker<Block>).check_header_proof(&RemoteHeaderRequest::<Header> {
+		assert_eq!((&local_checker as &dyn FetchChecker<Block>).check_header_proof(&RemoteHeaderRequest::<Header> {
 			cht_root: local_cht_root,
 			block: 1,
 			retry_count: None,
@@ -642,7 +642,7 @@ pub mod tests {
 	fn check_header_proof_fails_if_cht_root_is_invalid() {
 		let (local_checker, _, mut remote_block_header, remote_header_proof) = prepare_for_header_proof_check(true);
 		remote_block_header.number = 100;
-		assert!((&local_checker as &FetchChecker<Block>).check_header_proof(&RemoteHeaderRequest::<Header> {
+		assert!((&local_checker as &dyn FetchChecker<Block>).check_header_proof(&RemoteHeaderRequest::<Header> {
 			cht_root: Default::default(),
 			block: 1,
 			retry_count: None,
@@ -653,7 +653,7 @@ pub mod tests {
 	fn check_header_proof_fails_if_invalid_header_provided() {
 		let (local_checker, local_cht_root, mut remote_block_header, remote_header_proof) = prepare_for_header_proof_check(true);
 		remote_block_header.number = 100;
-		assert!((&local_checker as &FetchChecker<Block>).check_header_proof(&RemoteHeaderRequest::<Header> {
+		assert!((&local_checker as &dyn FetchChecker<Block>).check_header_proof(&RemoteHeaderRequest::<Header> {
 			cht_root: local_cht_root,
 			block: 1,
 			retry_count: None,
@@ -667,7 +667,7 @@ pub mod tests {
 			Arc::new(DummyBlockchain::new(DummyStorage::new())),
 			test_client::LocalExecutor::new(None)
 		);
-		let local_checker = &local_checker as &FetchChecker<Block>;
+		let local_checker = &local_checker as &dyn FetchChecker<Block>;
 		let max = remote_client.info().chain.best_number;
 		let max_hash = remote_client.info().chain.best_hash;
 
@@ -763,7 +763,7 @@ pub mod tests {
 			Arc::new(DummyBlockchain::new(DummyStorage::new())),
 			test_client::LocalExecutor::new(None)
 		);
-		let local_checker = &local_checker as &FetchChecker<Block>;
+		let local_checker = &local_checker as &dyn FetchChecker<Block>;
 		let max = remote_client.info().chain.best_number;
 		let max_hash = remote_client.info().chain.best_hash;
 
diff --git a/substrate/core/consensus/aura/src/lib.rs b/substrate/core/consensus/aura/src/lib.rs
index 263381d5f1..f0d982c36e 100644
--- a/substrate/core/consensus/aura/src/lib.rs
+++ b/substrate/core/consensus/aura/src/lib.rs
@@ -206,7 +206,7 @@ impl<H, B, C, E, I, P, Error, SO> SlotWorker<B> for AuraWorker<C, E, I, P, SO> w
 	DigestItemFor<B>: CompatibleDigestItem<P> + DigestItem<AuthorityId=AuthorityId<P>, Hash=B::Hash>,
 	Error: ::std::error::Error + Send + From<::consensus_common::Error> + From<I::Error> + 'static,
 {
-	type OnSlot = Box<Future<Item=(), Error=consensus_common::Error> + Send>;
+	type OnSlot = Box<dyn Future<Item=(), Error=consensus_common::Error> + Send>;
 
 	fn on_start(
 		&self,
@@ -578,7 +578,7 @@ impl<B: Block, C, E, P> Verifier<B> for AuraVerifier<C, E, P> where
 					// skip the inherents verification if the runtime API is old.
 					if self.client
 						.runtime_api()
-						.has_api_with::<BlockBuilderApi<B>, _>(&BlockId::Hash(parent_hash), |v| v >= 2)
+						.has_api_with::<dyn BlockBuilderApi<B>, _>(&BlockId::Hash(parent_hash), |v| v >= 2)
 						.map_err(|e| format!("{:?}", e))?
 					{
 						self.check_inherents(
@@ -681,7 +681,7 @@ fn authorities<B, C>(client: &C, at: &BlockId<B>) -> Result<Vec<AuthorityIdFor<B
 		.and_then(|cache| cache.get_at(&well_known_cache_keys::AUTHORITIES, at)
 			.and_then(|v| Decode::decode(&mut &v[..])))
 		.or_else(|| {
-			if client.runtime_api().has_api::<AuthoritiesApi<B>>(at).unwrap_or(false) {
+			if client.runtime_api().has_api::<dyn AuthoritiesApi<B>>(at).unwrap_or(false) {
 				AuthoritiesApi::authorities(&*client.runtime_api(), at).ok()
 			} else {
 				CoreApi::authorities(&*client.runtime_api(), at).ok()
diff --git a/substrate/core/consensus/babe/src/lib.rs b/substrate/core/consensus/babe/src/lib.rs
index 969c7b8593..12c388d329 100644
--- a/substrate/core/consensus/babe/src/lib.rs
+++ b/substrate/core/consensus/babe/src/lib.rs
@@ -251,7 +251,7 @@ impl<Hash, H, B, C, E, I, Error, SO> SlotWorker<B> for BabeWorker<C, E, I, SO> w
 	SO: SyncOracle + Send + Clone,
 	Error: std::error::Error + Send + From<::consensus_common::Error> + From<I::Error> + 'static,
 {
-	type OnSlot = Box<Future<Item=(), Error=consensus_common::Error> + Send>;
+	type OnSlot = Box<dyn Future<Item=(), Error=consensus_common::Error> + Send>;
 
 	fn on_start(
 		&self,
@@ -715,7 +715,7 @@ fn authorities<B, C>(client: &C, at: &BlockId<B>) -> Result<
 		.and_then(|cache| cache.get_at(&well_known_cache_keys::AUTHORITIES, at)
 			.and_then(|v| Decode::decode(&mut &v[..])))
 		.or_else(|| {
-			if client.runtime_api().has_api::<AuthoritiesApi<B>>(at).unwrap_or(false) {
+			if client.runtime_api().has_api::<dyn AuthoritiesApi<B>>(at).unwrap_or(false) {
 				AuthoritiesApi::authorities(&*client.runtime_api(), at).ok()
 			} else {
 				panic!("We don’t support deprecated code with new consensus algorithms, \
diff --git a/substrate/core/consensus/common/src/block_import.rs b/substrate/core/consensus/common/src/block_import.rs
index 1a6a8d1f50..8ce6019131 100644
--- a/substrate/core/consensus/common/src/block_import.rs
+++ b/substrate/core/consensus/common/src/block_import.rs
@@ -197,7 +197,7 @@ pub trait JustificationImport<B: BlockT> {
 	type Error: ::std::error::Error + Send + 'static;
 
 	/// Called by the import queue when it is started.
-	fn on_start(&self, _link: &crate::import_queue::Link<B>) { }
+	fn on_start(&self, _link: &dyn crate::import_queue::Link<B>) { }
 
 	/// Import a Block justification and finalize the given block.
 	fn import_justification(
@@ -210,10 +210,10 @@ pub trait JustificationImport<B: BlockT> {
 
 /// Finality proof import trait.
 pub trait FinalityProofImport<B: BlockT> {
-	type Error: ::std::error::Error + Send + 'static;
+	type Error: std::error::Error + Send + 'static;
 
 	/// Called by the import queue when it is started.
-	fn on_start(&self, _link: &crate::import_queue::Link<B>) { }
+	fn on_start(&self, _link: &dyn crate::import_queue::Link<B>) { }
 
 	/// Import a Block justification and finalize the given block. Returns finalized block or error.
 	fn import_finality_proof(
@@ -221,7 +221,7 @@ pub trait FinalityProofImport<B: BlockT> {
 		hash: B::Hash,
 		number: NumberFor<B>,
 		finality_proof: Vec<u8>,
-		verifier: &Verifier<B>,
+		verifier: &dyn Verifier<B>,
 	) -> Result<(B::Hash, NumberFor<B>), Self::Error>;
 }
 
diff --git a/substrate/core/consensus/common/src/error.rs b/substrate/core/consensus/common/src/error.rs
index a923c5f555..d8683d0b68 100644
--- a/substrate/core/consensus/common/src/error.rs
+++ b/substrate/core/consensus/common/src/error.rs
@@ -64,7 +64,7 @@ pub enum Error {
 	InvalidJustification,
 	/// Some other error.
 	#[display(fmt="Other error: {}", _0)]
-	Other(Box<error::Error + Send>),
+	Other(Box<dyn error::Error + Send>),
 	/// Error from the client while importing
 	#[display(fmt="Import failed: {}", _0)]
 	ClientImport(String),
diff --git a/substrate/core/consensus/common/src/import_queue.rs b/substrate/core/consensus/common/src/import_queue.rs
index d44aa0b93a..118bc641b2 100644
--- a/substrate/core/consensus/common/src/import_queue.rs
+++ b/substrate/core/consensus/common/src/import_queue.rs
@@ -103,7 +103,7 @@ pub trait ImportQueue<B: BlockT>: Send + Sync {
 	///
 	/// This is called automatically by the network service when synchronization
 	/// begins.
-	fn start(&self, _link: Box<Link<B>>) -> Result<(), std::io::Error> {
+	fn start(&self, _link: Box<dyn Link<B>>) -> Result<(), std::io::Error> {
 		Ok(())
 	}
 	/// Import bunch of blocks.
@@ -120,7 +120,7 @@ pub struct BasicSyncQueue<B: BlockT, V: Verifier<B>> {
 }
 
 struct BasicSyncQueueData<B: BlockT, V: Verifier<B>> {
-	link: Mutex<Option<Box<Link<B>>>>,
+	link: Mutex<Option<Box<dyn Link<B>>>>,
 	block_import: SharedBlockImport<B>,
 	verifier: Arc<V>,
 	justification_import: Option<SharedJustificationImport<B>>,
@@ -147,7 +147,7 @@ impl<B: BlockT, V: Verifier<B>> BasicSyncQueue<B, V> {
 }
 
 impl<B: BlockT, V: 'static + Verifier<B>> ImportQueue<B> for BasicSyncQueue<B, V> {
-	fn start(&self, link: Box<Link<B>>) -> Result<(), std::io::Error> {
+	fn start(&self, link: Box<dyn Link<B>>) -> Result<(), std::io::Error> {
 		if let Some(justification_import) = self.data.justification_import.as_ref() {
 			justification_import.on_start(&*link);
 		}
@@ -287,7 +287,7 @@ impl<B: BlockT> BasicQueue<B> {
 }
 
 impl<B: BlockT> ImportQueue<B> for BasicQueue<B> {
-	fn start(&self, link: Box<Link<B>>) -> Result<(), std::io::Error> {
+	fn start(&self, link: Box<dyn Link<B>>) -> Result<(), std::io::Error> {
 		let connect_err = || Err(std::io::Error::new(
 			std::io::ErrorKind::Other,
 			"Failed to connect import queue threads",
@@ -328,7 +328,7 @@ pub enum BlockImportMsg<B: BlockT> {
 	ImportBlocks(BlockOrigin, Vec<IncomingBlock<B>>),
 	ImportJustification(Origin, B::Hash, NumberFor<B>, Justification),
 	ImportFinalityProof(Origin, B::Hash, NumberFor<B>, Vec<u8>),
-	Start(Box<Link<B>>, Sender<Result<(), std::io::Error>>),
+	Start(Box<dyn Link<B>>, Sender<Result<(), std::io::Error>>),
 	Shutdown(Sender<()>),
 	#[cfg(any(test, feature = "test-helpers"))]
 	Synchronize,
@@ -360,7 +360,7 @@ struct BlockImporter<B: BlockT> {
 	result_port: Receiver<BlockImportWorkerMsg<B>>,
 	worker_sender: Option<Sender<BlockImportWorkerMsg<B>>>,
 	link: Option<Box<dyn Link<B>>>,
-	verifier: Arc<Verifier<B>>,
+	verifier: Arc<dyn Verifier<B>>,
 	justification_import: Option<SharedJustificationImport<B>>,
 	finality_proof_import: Option<SharedFinalityProofImport<B>>,
 	finality_proof_request_builder: Option<SharedFinalityProofRequestBuilder<B>>,
@@ -370,7 +370,7 @@ impl<B: BlockT> BlockImporter<B> {
 	fn new(
 		result_port: Receiver<BlockImportWorkerMsg<B>>,
 		worker_sender: Sender<BlockImportWorkerMsg<B>>,
-		verifier: Arc<Verifier<B>>,
+		verifier: Arc<dyn Verifier<B>>,
 		justification_import: Option<SharedJustificationImport<B>>,
 		finality_proof_import: Option<SharedFinalityProofImport<B>>,
 		finality_proof_request_builder: Option<SharedFinalityProofRequestBuilder<B>>,
@@ -667,7 +667,7 @@ pub enum BlockImportError {
 
 /// Imports single notification and send notification to the link (if provided).
 fn import_single_justification<B: BlockT>(
-	link: &Option<Box<Link<B>>>,
+	link: &Option<Box<dyn Link<B>>>,
 	justification_import: &Option<SharedJustificationImport<B>>,
 	who: Origin,
 	hash: B::Hash,
@@ -723,7 +723,7 @@ fn import_single_finality_proof<B: BlockT, V: Verifier<B>>(
 
 /// Process result of block(s) import.
 fn process_import_results<B: BlockT>(
-	link: &Link<B>,
+	link: &dyn Link<B>,
 	results: Vec<(
 		Result<BlockImportResult<NumberFor<B>>, BlockImportError>,
 		B::Hash,
@@ -801,7 +801,7 @@ fn process_import_results<B: BlockT>(
 
 /// Import several blocks at once, returning import result for each block.
 fn import_many_blocks<B: BlockT, V: Verifier<B>>(
-	import_handle: &BlockImport<B, Error = ConsensusError>,
+	import_handle: &dyn BlockImport<B, Error = ConsensusError>,
 	blocks_origin: BlockOrigin,
 	blocks: Vec<IncomingBlock<B>>,
 	verifier: Arc<V>,
@@ -854,7 +854,7 @@ fn import_many_blocks<B: BlockT, V: Verifier<B>>(
 
 /// Single block import function.
 pub fn import_single_block<B: BlockT, V: Verifier<B>>(
-	import_handle: &BlockImport<B, Error = ConsensusError>,
+	import_handle: &dyn BlockImport<B, Error = ConsensusError>,
 	block_origin: BlockOrigin,
 	block: IncomingBlock<B>,
 	verifier: Arc<V>,
diff --git a/substrate/core/executor/src/native_executor.rs b/substrate/core/executor/src/native_executor.rs
index 729346cbee..c4f3511c9c 100644
--- a/substrate/core/executor/src/native_executor.rs
+++ b/substrate/core/executor/src/native_executor.rs
@@ -107,7 +107,7 @@ fn safe_call<F, U>(f: F) -> Result<U>
 /// Set up the externalities and safe calling environment to execute calls to a native runtime.
 ///
 /// If the inner closure panics, it will be caught and return an error.
-pub fn with_native_environment<F, U>(ext: &mut Externalities<Blake2Hasher>, f: F) -> Result<U>
+pub fn with_native_environment<F, U>(ext: &mut dyn Externalities<Blake2Hasher>, f: F) -> Result<U>
 	where F: UnwindSafe + FnOnce() -> U
 {
 	::runtime_io::with_externalities(ext, move || safe_call(f))
@@ -121,7 +121,7 @@ pub trait NativeExecutionDispatch: Send + Sync {
 	/// Dispatch a method and input data to be executed natively. Returns `Some` result or `None`
 	/// if the `method` is unknown. Panics if there's an unrecoverable error.
 	// fn dispatch<H: hash_db::Hasher>(ext: &mut Externalities<H>, method: &str, data: &[u8]) -> Result<Vec<u8>>;
-	fn dispatch(ext: &mut Externalities<Blake2Hasher>, method: &str, data: &[u8]) -> Result<Vec<u8>>;
+	fn dispatch(ext: &mut dyn Externalities<Blake2Hasher>, method: &str, data: &[u8]) -> Result<Vec<u8>>;
 
 	/// Provide native runtime version.
 	fn native_version() -> NativeVersion;
diff --git a/substrate/core/executor/src/wasm_executor.rs b/substrate/core/executor/src/wasm_executor.rs
index 6a3c92b755..920639c0a2 100644
--- a/substrate/core/executor/src/wasm_executor.rs
+++ b/substrate/core/executor/src/wasm_executor.rs
@@ -1101,7 +1101,7 @@ impl WasmExecutor {
 	/// This should be used for tests only.
 	pub fn call_with_custom_signature<
 		E: Externalities<Blake2Hasher>,
-		F: FnOnce(&mut FnMut(&[u8]) -> Result<u32>) -> Result<Vec<RuntimeValue>>,
+		F: FnOnce(&mut dyn FnMut(&[u8]) -> Result<u32>) -> Result<Vec<RuntimeValue>>,
 		FR: FnOnce(Option<RuntimeValue>, &MemoryRef) -> Result<Option<R>>,
 		R,
 	>(
@@ -1158,7 +1158,7 @@ impl WasmExecutor {
 	/// Call a given method in the given wasm-module runtime.
 	fn call_in_wasm_module_with_custom_signature<
 		E: Externalities<Blake2Hasher>,
-		F: FnOnce(&mut FnMut(&[u8]) -> Result<u32>) -> Result<Vec<RuntimeValue>>,
+		F: FnOnce(&mut dyn FnMut(&[u8]) -> Result<u32>) -> Result<Vec<RuntimeValue>>,
 		FR: FnOnce(Option<RuntimeValue>, &MemoryRef) -> Result<Option<R>>,
 		R,
 	>(
diff --git a/substrate/core/executor/src/wasm_utils.rs b/substrate/core/executor/src/wasm_utils.rs
index a9fbca7f6c..7384f91944 100644
--- a/substrate/core/executor/src/wasm_utils.rs
+++ b/substrate/core/executor/src/wasm_utils.rs
@@ -174,7 +174,7 @@ macro_rules! impl_function_executor {
 	  => $($pre:tt)+ ) => (
 		impl $( $pre ) + $structname {
 			#[allow(unused)]
-			fn resolver() -> &'static $crate::wasmi::ModuleImportResolver {
+			fn resolver() -> &'static dyn $crate::wasmi::ModuleImportResolver {
 				struct Resolver;
 				impl $crate::wasmi::ModuleImportResolver for Resolver {
 					fn resolve_func(&self, name: &str, signature: &$crate::wasmi::Signature) -> ::std::result::Result<$crate::wasmi::FuncRef, $crate::wasmi::Error> {
diff --git a/substrate/core/finality-grandpa/src/communication/gossip.rs b/substrate/core/finality-grandpa/src/communication/gossip.rs
index 79f98e5bdb..460998e707 100644
--- a/substrate/core/finality-grandpa/src/communication/gossip.rs
+++ b/substrate/core/finality-grandpa/src/communication/gossip.rs
@@ -657,7 +657,7 @@ impl<Block: BlockT> GossipValidator<Block> {
 }
 
 impl<Block: BlockT> network_gossip::Validator<Block> for GossipValidator<Block> {
-	fn new_peer(&self, context: &mut ValidatorContext<Block>, who: &PeerId, _roles: Roles) {
+	fn new_peer(&self, context: &mut dyn ValidatorContext<Block>, who: &PeerId, _roles: Roles) {
 		let packet_data = {
 			let mut inner = self.inner.write();
 			inner.peers.new_peer(who.clone());
@@ -673,11 +673,11 @@ impl<Block: BlockT> network_gossip::Validator<Block> for GossipValidator<Block>
 		context.send_message(who, packet_data);
 	}
 
-	fn peer_disconnected(&self, _context: &mut ValidatorContext<Block>, who: &PeerId) {
+	fn peer_disconnected(&self, _context: &mut dyn ValidatorContext<Block>, who: &PeerId) {
 		self.inner.write().peers.peer_disconnected(who);
 	}
 
-	fn validate(&self, context: &mut ValidatorContext<Block>, who: &PeerId, data: &[u8])
+	fn validate(&self, context: &mut dyn ValidatorContext<Block>, who: &PeerId, data: &[u8])
 		-> network_gossip::ValidationResult<Block::Hash>
 	{
 		let (action, broadcast_topics) = self.do_validate(who, data);
@@ -705,7 +705,7 @@ impl<Block: BlockT> network_gossip::Validator<Block> for GossipValidator<Block>
 	}
 
 	fn message_allowed<'a>(&'a self)
-		-> Box<FnMut(&PeerId, MessageIntent, &Block::Hash, &[u8]) -> bool + 'a>
+		-> Box<dyn FnMut(&PeerId, MessageIntent, &Block::Hash, &[u8]) -> bool + 'a>
 	{
 		let (inner, do_rebroadcast) = {
 			use parking_lot::RwLockWriteGuard;
@@ -763,7 +763,7 @@ impl<Block: BlockT> network_gossip::Validator<Block> for GossipValidator<Block>
 		})
 	}
 
-	fn message_expired<'a>(&'a self) -> Box<FnMut(Block::Hash, &[u8]) -> bool + 'a> {
+	fn message_expired<'a>(&'a self) -> Box<dyn FnMut(Block::Hash, &[u8]) -> bool + 'a> {
 		let inner = self.inner.read();
 		Box::new(move |topic, mut data| {
 			// if the topic is not one of the ones that we are keeping at the moment,
diff --git a/substrate/core/finality-grandpa/src/finality_proof.rs b/substrate/core/finality-grandpa/src/finality_proof.rs
index e8af599279..875a60e8e0 100644
--- a/substrate/core/finality-grandpa/src/finality_proof.rs
+++ b/substrate/core/finality-grandpa/src/finality_proof.rs
@@ -103,7 +103,7 @@ pub trait AuthoritySetForFinalityChecker<Block: BlockT>: Send + Sync {
 }
 
 /// FetchChecker-based implementation of AuthoritySetForFinalityChecker.
-impl<Block: BlockT> AuthoritySetForFinalityChecker<Block> for Arc<FetchChecker<Block>> {
+impl<Block: BlockT> AuthoritySetForFinalityChecker<Block> for Arc<dyn FetchChecker<Block>> {
 	fn check_authorities_proof(
 		&self,
 		hash: Block::Hash,
@@ -132,7 +132,7 @@ impl<Block: BlockT> AuthoritySetForFinalityChecker<Block> for Arc<FetchChecker<B
 /// Finality proof provider for serving network requests.
 pub struct FinalityProofProvider<B, E, Block: BlockT<Hash=H256>, RA> {
 	client: Arc<Client<B, E, Block, RA>>,
-	authority_provider: Arc<AuthoritySetForFinalityProver<Block>>,
+	authority_provider: Arc<dyn AuthoritySetForFinalityProver<Block>>,
 }
 
 impl<B, E, Block: BlockT<Hash=H256>, RA> FinalityProofProvider<B, E, Block, RA>
@@ -147,7 +147,7 @@ impl<B, E, Block: BlockT<Hash=H256>, RA> FinalityProofProvider<B, E, Block, RA>
 	/// - authority_provider for calling and proving runtime methods.
 	pub fn new(
 		client: Arc<Client<B, E, Block, RA>>,
-		authority_provider: Arc<AuthoritySetForFinalityProver<Block>>,
+		authority_provider: Arc<dyn AuthoritySetForFinalityProver<Block>>,
 	) -> Self {
 		FinalityProofProvider { client, authority_provider }
 	}
@@ -256,7 +256,7 @@ pub(crate) fn make_finality_proof_request<H: Encode + Decode>(last_finalized: H,
 /// Returns None if there are no finalized blocks unknown to the caller.
 pub(crate) fn prove_finality<Block: BlockT<Hash=H256>, B: BlockchainBackend<Block>, J>(
 	blockchain: &B,
-	authorities_provider: &AuthoritySetForFinalityProver<Block>,
+	authorities_provider: &dyn AuthoritySetForFinalityProver<Block>,
 	authorities_set_id: u64,
 	begin: Block::Hash,
 	end: Block::Hash,
@@ -416,7 +416,7 @@ pub(crate) fn check_finality_proof<Block: BlockT<Hash=H256>, B>(
 	blockchain: &B,
 	current_set_id: u64,
 	current_authorities: Vec<(AuthorityId, u64)>,
-	authorities_provider: &AuthoritySetForFinalityChecker<Block>,
+	authorities_provider: &dyn AuthoritySetForFinalityChecker<Block>,
 	remote_proof: Vec<u8>,
 ) -> ClientResult<FinalityEffects<Block::Header>>
 	where
@@ -435,7 +435,7 @@ fn do_check_finality_proof<Block: BlockT<Hash=H256>, B, J>(
 	blockchain: &B,
 	current_set_id: u64,
 	current_authorities: Vec<(AuthorityId, u64)>,
-	authorities_provider: &AuthoritySetForFinalityChecker<Block>,
+	authorities_provider: &dyn AuthoritySetForFinalityChecker<Block>,
 	remote_proof: Vec<u8>,
 ) -> ClientResult<FinalityEffects<Block::Header>>
 	where
@@ -489,7 +489,7 @@ fn do_check_finality_proof<Block: BlockT<Hash=H256>, B, J>(
 fn check_finality_proof_fragment<Block: BlockT<Hash=H256>, B, J>(
 	blockchain: &B,
 	authority_set: AuthoritiesOrEffects<Block::Header>,
-	authorities_provider: &AuthoritySetForFinalityChecker<Block>,
+	authorities_provider: &dyn AuthoritySetForFinalityChecker<Block>,
 	proof_fragment: FinalityProofFragment<Block::Header>,
 ) -> ClientResult<AuthoritiesOrEffects<Block::Header>>
 	where
diff --git a/substrate/core/finality-grandpa/src/import.rs b/substrate/core/finality-grandpa/src/import.rs
index d68793c047..ed57c68250 100644
--- a/substrate/core/finality-grandpa/src/import.rs
+++ b/substrate/core/finality-grandpa/src/import.rs
@@ -76,7 +76,7 @@ impl<B, E, Block: BlockT<Hash=H256>, RA, PRA, SC> JustificationImport<Block>
 {
 	type Error = ConsensusError;
 
-	fn on_start(&self, link: &::consensus_common::import_queue::Link<Block>) {
+	fn on_start(&self, link: &dyn consensus_common::import_queue::Link<Block>) {
 		let chain_info = self.inner.info().chain;
 
 		// request justifications for all pending changes for which change blocks have already been imported
@@ -183,7 +183,7 @@ where
 			);
 
 			match maybe_change {
-				Err(e) => match api.has_api_with::<GrandpaApi<Block>, _>(&at, |v| v >= 2) {
+				Err(e) => match api.has_api_with::<dyn GrandpaApi<Block>, _>(&at, |v| v >= 2) {
 					Err(e) => return Err(ConsensusError::ClientImport(e.to_string()).into()),
 					Ok(true) => {
 						// API version is high enough to support forced changes
diff --git a/substrate/core/finality-grandpa/src/light_import.rs b/substrate/core/finality-grandpa/src/light_import.rs
index 73bc3411fe..c70f91d0f3 100644
--- a/substrate/core/finality-grandpa/src/light_import.rs
+++ b/substrate/core/finality-grandpa/src/light_import.rs
@@ -53,7 +53,7 @@ const LIGHT_CONSENSUS_CHANGES_KEY: &[u8] = b"grandpa_consensus_changes";
 /// Create light block importer.
 pub fn light_block_import<B, E, Block: BlockT<Hash=H256>, RA, PRA>(
 	client: Arc<Client<B, E, Block, RA>>,
-	authority_set_provider: Arc<AuthoritySetForFinalityChecker<Block>>,
+	authority_set_provider: Arc<dyn AuthoritySetForFinalityChecker<Block>>,
 	api: Arc<PRA>,
 ) -> Result<GrandpaLightBlockImport<B, E, Block, RA>, ClientError>
 	where
@@ -80,7 +80,7 @@ pub fn light_block_import<B, E, Block: BlockT<Hash=H256>, RA, PRA>(
 /// - fetching finality proofs for blocks that are enacting consensus changes.
 pub struct GrandpaLightBlockImport<B, E, Block: BlockT<Hash=H256>, RA> {
 	client: Arc<Client<B, E, Block, RA>>,
-	authority_set_provider: Arc<AuthoritySetForFinalityChecker<Block>>,
+	authority_set_provider: Arc<dyn AuthoritySetForFinalityChecker<Block>>,
 	data: Arc<RwLock<LightImportData<Block>>>,
 }
 
@@ -144,7 +144,7 @@ impl<B, E, Block: BlockT<Hash=H256>, RA> FinalityProofImport<Block>
 {
 	type Error = ConsensusError;
 
-	fn on_start(&self, link: &::consensus_common::import_queue::Link<Block>) {
+	fn on_start(&self, link: &dyn consensus_common::import_queue::Link<Block>) {
 		let chain_info = self.client.info().chain;
 
 		let data = self.data.read();
@@ -160,7 +160,7 @@ impl<B, E, Block: BlockT<Hash=H256>, RA> FinalityProofImport<Block>
 		hash: Block::Hash,
 		number: NumberFor<Block>,
 		finality_proof: Vec<u8>,
-		verifier: &Verifier<Block>,
+		verifier: &dyn Verifier<Block>,
 	) -> Result<(Block::Hash, NumberFor<Block>), Self::Error> {
 		do_import_finality_proof::<_, _, _, _, GrandpaJustification<Block>>(
 			&*self.client,
@@ -271,12 +271,12 @@ fn do_import_block<B, E, Block: BlockT<Hash=H256>, RA, J>(
 /// Try to import finality proof.
 fn do_import_finality_proof<B, E, Block: BlockT<Hash=H256>, RA, J>(
 	client: &Client<B, E, Block, RA>,
-	authority_set_provider: &AuthoritySetForFinalityChecker<Block>,
+	authority_set_provider: &dyn AuthoritySetForFinalityChecker<Block>,
 	data: &mut LightImportData<Block>,
 	_hash: Block::Hash,
 	_number: NumberFor<Block>,
 	finality_proof: Vec<u8>,
-	verifier: &Verifier<Block>,
+	verifier: &dyn Verifier<Block>,
 ) -> Result<(Block::Hash, NumberFor<Block>), ConsensusError>
 	where
 		B: Backend<Block, Blake2Hasher> + 'static,
@@ -572,7 +572,7 @@ pub mod tests {
 	{
 		type Error = ConsensusError;
 
-		fn on_start(&self, link: &::consensus_common::import_queue::Link<Block>) {
+		fn on_start(&self, link: &dyn consensus_common::import_queue::Link<Block>) {
 			self.0.on_start(link)
 		}
 
@@ -581,7 +581,7 @@ pub mod tests {
 			hash: Block::Hash,
 			number: NumberFor<Block>,
 			finality_proof: Vec<u8>,
-			verifier: &Verifier<Block>,
+			verifier: &dyn Verifier<Block>,
 		) -> Result<(Block::Hash, NumberFor<Block>), Self::Error> {
 			self.0.import_finality_proof(hash, number, finality_proof, verifier)
 		}
@@ -590,7 +590,7 @@ pub mod tests {
 	/// Creates light block import that ignores justifications that came outside of finality proofs.
 	pub fn light_block_import_without_justifications<B, E, Block: BlockT<Hash=H256>, RA, PRA>(
 		client: Arc<Client<B, E, Block, RA>>,
-		authority_set_provider: Arc<AuthoritySetForFinalityChecker<Block>>,
+		authority_set_provider: Arc<dyn AuthoritySetForFinalityChecker<Block>>,
 		api: Arc<PRA>,
 	) -> Result<NoJustificationsImport<B, E, Block, RA>, ClientError>
 		where
diff --git a/substrate/core/finality-grandpa/src/tests.rs b/substrate/core/finality-grandpa/src/tests.rs
index ef04396b5f..51028fad84 100644
--- a/substrate/core/finality-grandpa/src/tests.rs
+++ b/substrate/core/finality-grandpa/src/tests.rs
@@ -150,7 +150,10 @@ impl TestNetFactory for GrandpaTestNet {
 		}
 	}
 
-	fn make_finality_proof_provider(&self, client: PeersClient) -> Option<Arc<network::FinalityProofProvider<Block>>> {
+	fn make_finality_proof_provider(
+		&self,
+		client: PeersClient
+	) -> Option<Arc<dyn network::FinalityProofProvider<Block>>> {
 		match client {
 			PeersClient::Full(ref client) => {
 				let authorities_provider = Arc::new(self.test_config.clone());
@@ -201,7 +204,7 @@ impl MessageRouting {
 }
 
 impl Network<Block> for MessageRouting {
-	type In = Box<Stream<Item=network_gossip::TopicNotification, Error=()> + Send>;
+	type In = Box<dyn Stream<Item=network_gossip::TopicNotification, Error=()> + Send>;
 
 	/// Get a stream of messages for a specific gossip topic.
 	fn messages_for(&self, topic: Hash) -> Self::In {
@@ -463,7 +466,7 @@ fn run_to_completion_with<F>(
 	peers: &[AuthorityKeyring],
 	with: F,
 ) -> u64 where
-	F: FnOnce(current_thread::Handle) -> Option<Box<Future<Item=(),Error=()>>>
+	F: FnOnce(current_thread::Handle) -> Option<Box<dyn Future<Item=(), Error=()>>>
 {
 	use parking_lot::RwLock;
 
diff --git a/substrate/core/keyring/src/sr25519.rs b/substrate/core/keyring/src/sr25519.rs
index 0097d7b2f9..24a83ab798 100644
--- a/substrate/core/keyring/src/sr25519.rs
+++ b/substrate/core/keyring/src/sr25519.rs
@@ -68,7 +68,7 @@ impl Keyring {
 	}
 
 	pub fn to_raw_public_vec(self) -> Vec<u8> {
-		Public::from(self).to_raw_vec()
+		Public::from(self).into_raw_vec()
 	}
 
 	pub fn sign(self, msg: &[u8]) -> Signature {
diff --git a/substrate/core/network/src/config.rs b/substrate/core/network/src/config.rs
index e6c1a4ddd5..d8fd0f68c7 100644
--- a/substrate/core/network/src/config.rs
+++ b/substrate/core/network/src/config.rs
@@ -35,9 +35,9 @@ pub struct Params<B: BlockT, S, H: ExHashT> {
 	/// Network layer configuration.
 	pub network_config: NetworkConfiguration,
 	/// Substrate relay chain access point.
-	pub chain: Arc<Client<B>>,
+	pub chain: Arc<dyn Client<B>>,
 	/// Finality proof provider.
-	pub finality_proof_provider: Option<Arc<FinalityProofProvider<B>>>,
+	pub finality_proof_provider: Option<Arc<dyn FinalityProofProvider<B>>>,
 	/// On-demand service reference.
 	pub on_demand: Option<Arc<OnDemand<B>>>,
 	/// Transaction pool.
@@ -45,7 +45,7 @@ pub struct Params<B: BlockT, S, H: ExHashT> {
 	/// Name of the protocol to use on the wire. Should be different for each chain.
 	pub protocol_id: ProtocolId,
 	/// Import queue to use.
-	pub import_queue: Box<ImportQueue<B>>,
+	pub import_queue: Box<dyn ImportQueue<B>>,
 	/// Protocol specialization.
 	pub specialization: S,
 }
diff --git a/substrate/core/network/src/consensus_gossip.rs b/substrate/core/network/src/consensus_gossip.rs
index c5f1a2d927..9d654b5bfa 100644
--- a/substrate/core/network/src/consensus_gossip.rs
+++ b/substrate/core/network/src/consensus_gossip.rs
@@ -110,7 +110,7 @@ pub trait ValidatorContext<B: BlockT> {
 
 struct NetworkContext<'g, 'p, B: BlockT> {
 	gossip: &'g mut ConsensusGossip<B>,
-	protocol: &'p mut Context<B>,
+	protocol: &'p mut dyn Context<B>,
 	engine_id: ConsensusEngineId,
 }
 
@@ -145,11 +145,11 @@ impl<'g, 'p, B: BlockT> ValidatorContext<B> for NetworkContext<'g, 'p, B> {
 }
 
 fn propagate<'a, B: BlockT, I>(
-	protocol: &mut Context<B>,
+	protocol: &mut dyn Context<B>,
 	messages: I,
 	intent: MessageIntent,
 	peers: &mut HashMap<PeerId, PeerConsensus<B::Hash>>,
-	validators: &HashMap<ConsensusEngineId, Arc<Validator<B>>>,
+	validators: &HashMap<ConsensusEngineId, Arc<dyn Validator<B>>>,
 )
 	where I: IntoIterator<Item=(&'a B::Hash, &'a B::Hash, &'a ConsensusMessage)>,  // (msg_hash, topic, message)
 {
@@ -200,23 +200,23 @@ fn propagate<'a, B: BlockT, I>(
 /// Validates consensus messages.
 pub trait Validator<B: BlockT>: Send + Sync {
 	/// New peer is connected.
-	fn new_peer(&self, _context: &mut ValidatorContext<B>, _who: &PeerId, _roles: Roles) {
+	fn new_peer(&self, _context: &mut dyn ValidatorContext<B>, _who: &PeerId, _roles: Roles) {
 	}
 
 	/// New connection is dropped.
-	fn peer_disconnected(&self, _context: &mut ValidatorContext<B>, _who: &PeerId) {
+	fn peer_disconnected(&self, _context: &mut dyn ValidatorContext<B>, _who: &PeerId) {
 	}
 
 	/// Validate consensus message.
-	fn validate(&self, context: &mut ValidatorContext<B>, sender: &PeerId, data: &[u8]) -> ValidationResult<B::Hash>;
+	fn validate(&self, context: &mut dyn ValidatorContext<B>, sender: &PeerId, data: &[u8]) -> ValidationResult<B::Hash>;
 
 	/// Produce a closure for validating messages on a given topic.
-	fn message_expired<'a>(&'a self) -> Box<FnMut(B::Hash, &[u8]) -> bool + 'a> {
+	fn message_expired<'a>(&'a self) -> Box<dyn FnMut(B::Hash, &[u8]) -> bool + 'a> {
 		Box::new(move |_topic, _data| false)
 	}
 
 	/// Produce a closure for filtering egress messages.
-	fn message_allowed<'a>(&'a self) -> Box<FnMut(&PeerId, MessageIntent, &B::Hash, &[u8]) -> bool + 'a> {
+	fn message_allowed<'a>(&'a self) -> Box<dyn FnMut(&PeerId, MessageIntent, &B::Hash, &[u8]) -> bool + 'a> {
 		Box::new(move |_who, _intent, _topic, _data| true)
 	}
 }
@@ -227,7 +227,7 @@ pub struct ConsensusGossip<B: BlockT> {
 	live_message_sinks: HashMap<(ConsensusEngineId, B::Hash), Vec<mpsc::UnboundedSender<TopicNotification>>>,
 	messages: Vec<MessageEntry<B>>,
 	known_messages: LruCache<B::Hash, ()>,
-	validators: HashMap<ConsensusEngineId, Arc<Validator<B>>>,
+	validators: HashMap<ConsensusEngineId, Arc<dyn Validator<B>>>,
 	next_broadcast: time::Instant,
 }
 
@@ -250,7 +250,12 @@ impl<B: BlockT> ConsensusGossip<B> {
 	}
 
 	/// Register message validator for a message type.
-	pub fn register_validator(&mut self, protocol: &mut Context<B>, engine_id: ConsensusEngineId, validator: Arc<Validator<B>>) {
+	pub fn register_validator(
+		&mut self,
+		protocol: &mut dyn Context<B>,
+		engine_id: ConsensusEngineId,
+		validator: Arc<dyn Validator<B>>
+	) {
 		self.register_validator_internal(engine_id, validator.clone());
 		let peers: Vec<_> = self.peers.iter().map(|(id, peer)| (id.clone(), peer.roles)).collect();
 		for (id, roles) in peers {
@@ -259,12 +264,12 @@ impl<B: BlockT> ConsensusGossip<B> {
 		}
 	}
 
-	fn register_validator_internal(&mut self, engine_id: ConsensusEngineId, validator: Arc<Validator<B>>) {
+	fn register_validator_internal(&mut self, engine_id: ConsensusEngineId, validator: Arc<dyn Validator<B>>) {
 		self.validators.insert(engine_id, validator.clone());
 	}
 
 	/// Handle new connected peer.
-	pub fn new_peer(&mut self, protocol: &mut Context<B>, who: PeerId, roles: Roles) {
+	pub fn new_peer(&mut self, protocol: &mut dyn Context<B>, who: PeerId, roles: Roles) {
 		// light nodes are not valid targets for consensus gossip messages
 		if !roles.is_full() {
 			return;
@@ -311,7 +316,7 @@ impl<B: BlockT> ConsensusGossip<B> {
 	}
 
 	/// Call when a peer has been disconnected to stop tracking gossip status.
-	pub fn peer_disconnected(&mut self, protocol: &mut Context<B>, who: PeerId) {
+	pub fn peer_disconnected(&mut self, protocol: &mut dyn Context<B>, who: PeerId) {
 		for (engine_id, v) in self.validators.clone() {
 			let mut context = NetworkContext { gossip: self, protocol, engine_id: engine_id.clone() };
 			v.peer_disconnected(&mut context, &who);
@@ -319,7 +324,7 @@ impl<B: BlockT> ConsensusGossip<B> {
 	}
 
 	/// Perform periodic maintenance
-	pub fn tick(&mut self, protocol: &mut Context<B>) {
+	pub fn tick(&mut self, protocol: &mut dyn Context<B>) {
 		self.collect_garbage();
 		if time::Instant::now() >= self.next_broadcast {
 			self.rebroadcast(protocol);
@@ -328,14 +333,14 @@ impl<B: BlockT> ConsensusGossip<B> {
 	}
 
 	/// Rebroadcast all messages to all peers.
-	fn rebroadcast(&mut self, protocol: &mut Context<B>) {
+	fn rebroadcast(&mut self, protocol: &mut dyn Context<B>) {
 		let messages = self.messages.iter()
 			.map(|entry| (&entry.message_hash, &entry.topic, &entry.message));
 		propagate(protocol, messages, MessageIntent::PeriodicRebroadcast, &mut self.peers, &self.validators);
 	}
 
 	/// Broadcast all messages with given topic.
-	pub fn broadcast_topic(&mut self, protocol: &mut Context<B>, topic: B::Hash, force: bool) {
+	pub fn broadcast_topic(&mut self, protocol: &mut dyn Context<B>, topic: B::Hash, force: bool) {
 		let messages = self.messages.iter()
 			.filter_map(|entry|
 				if entry.topic == topic { Some((&entry.message_hash, &entry.topic, &entry.message)) } else { None }
@@ -409,7 +414,7 @@ impl<B: BlockT> ConsensusGossip<B> {
 	/// in all other cases.
 	pub fn on_incoming(
 		&mut self,
-		protocol: &mut Context<B>,
+		protocol: &mut dyn Context<B>,
 		who: PeerId,
 		message: ConsensusMessage,
 	) {
@@ -473,7 +478,14 @@ impl<B: BlockT> ConsensusGossip<B> {
 	}
 
 	/// Send all messages with given topic to a peer.
-	pub fn send_topic(&mut self, protocol: &mut Context<B>, who: &PeerId, topic: B::Hash, engine_id: ConsensusEngineId, force: bool) {
+	pub fn send_topic(
+		&mut self,
+		protocol: &mut dyn Context<B>,
+		who: &PeerId,
+		topic: B::Hash,
+		engine_id: ConsensusEngineId,
+		force: bool
+	) {
 		let validator = self.validators.get(&engine_id);
 		let mut message_allowed = match validator {
 			None => return, // treat all messages with no validator as not allowed
@@ -503,7 +515,7 @@ impl<B: BlockT> ConsensusGossip<B> {
 	/// Multicast a message to all peers.
 	pub fn multicast(
 		&mut self,
-		protocol: &mut Context<B>,
+		protocol: &mut dyn Context<B>,
 		topic: B::Hash,
 		message: ConsensusMessage,
 		force: bool,
@@ -518,7 +530,7 @@ impl<B: BlockT> ConsensusGossip<B> {
 	/// later on.
 	pub fn send_message(
 		&mut self,
-		protocol: &mut Context<B>,
+		protocol: &mut dyn Context<B>,
 		who: &PeerId,
 		message: ConsensusMessage,
 	) {
@@ -559,7 +571,12 @@ mod tests {
 
 	struct AllowAll;
 	impl Validator<Block> for AllowAll {
-		fn validate(&self, _context: &mut ValidatorContext<Block>, _sender: &PeerId, _data: &[u8]) -> ValidationResult<H256> {
+		fn validate(
+			&self,
+			_context: &mut dyn ValidatorContext<Block>,
+			_sender: &PeerId,
+			_data: &[u8],
+		) -> ValidationResult<H256> {
 			ValidationResult::ProcessAndKeep(H256::default())
 		}
 	}
@@ -568,7 +585,12 @@ mod tests {
 	fn collects_garbage() {
 		struct AllowOne;
 		impl Validator<Block> for AllowOne {
-			fn validate(&self, _context: &mut ValidatorContext<Block>, _sender: &PeerId, data: &[u8]) -> ValidationResult<H256> {
+			fn validate(
+				&self,
+				_context: &mut dyn ValidatorContext<Block>,
+				_sender: &PeerId,
+				data: &[u8],
+			) -> ValidationResult<H256> {
 				if data[0] == 1 {
 					ValidationResult::ProcessAndKeep(H256::default())
 				} else {
@@ -576,7 +598,7 @@ mod tests {
 				}
 			}
 
-			fn message_expired<'a>(&'a self) -> Box<FnMut(H256, &[u8]) -> bool + 'a> {
+			fn message_expired<'a>(&'a self) -> Box<dyn FnMut(H256, &[u8]) -> bool + 'a> {
 				Box::new(move |_topic, data| data[0] != 1 )
 			}
 		}
diff --git a/substrate/core/network/src/on_demand_layer.rs b/substrate/core/network/src/on_demand_layer.rs
index 95f9f4d67b..e58e045f2e 100644
--- a/substrate/core/network/src/on_demand_layer.rs
+++ b/substrate/core/network/src/on_demand_layer.rs
@@ -50,7 +50,7 @@ impl<B: BlockT> OnDemand<B> where
 	B::Header: HeaderT,
 {
 	/// Creates new on-demand service.
-	pub fn new(checker: Arc<FetchChecker<B>>) -> Self {
+	pub fn new(checker: Arc<dyn FetchChecker<B>>) -> Self {
 		let (requests_send, requests_queue) = mpsc::unbounded();
 		let requests_queue = Mutex::new(Some(requests_queue));
 
@@ -62,7 +62,7 @@ impl<B: BlockT> OnDemand<B> where
 	}
 
 	/// Get checker reference.
-	pub fn checker(&self) -> &Arc<FetchChecker<B>> {
+	pub fn checker(&self) -> &Arc<dyn FetchChecker<B>> {
 		&self.checker
 	}
 
diff --git a/substrate/core/network/src/protocol.rs b/substrate/core/network/src/protocol.rs
index b660e097a1..569f1df030 100644
--- a/substrate/core/network/src/protocol.rs
+++ b/substrate/core/network/src/protocol.rs
@@ -346,7 +346,7 @@ impl<'a, B: BlockT + 'a, H: ExHashT + 'a> SyncContext<B> for ProtocolContext<'a,
 		self.context_data.peers.get(who).map(|p| p.info.clone())
 	}
 
-	fn client(&self) -> &Client<B> {
+	fn client(&self) -> &dyn Client<B> {
 		&*self.context_data.chain
 	}
 
@@ -373,7 +373,7 @@ impl<'a, B: BlockT + 'a, H: ExHashT + 'a> SyncContext<B> for ProtocolContext<'a,
 struct ContextData<B: BlockT, H: ExHashT> {
 	// All connected peers
 	peers: HashMap<PeerId, Peer<B, H>>,
-	pub chain: Arc<Client<B>>,
+	pub chain: Arc<dyn Client<B>>,
 }
 
 /// Configuration for the Substrate-specific part of the networking layer.
@@ -395,7 +395,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 	/// Create a new instance.
 	pub fn new(
 		config: ProtocolConfig,
-		chain: Arc<Client<B>>,
+		chain: Arc<dyn Client<B>>,
 		checker: Arc<dyn FetchChecker<B>>,
 		specialization: S,
 	) -> error::Result<Protocol<B, S, H>> {
@@ -510,7 +510,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 		transaction_pool: &(impl TransactionPool<H, B> + ?Sized),
 		who: PeerId,
 		message: Message<B>,
-		finality_proof_provider: Option<&FinalityProofProvider<B>>
+		finality_proof_provider: Option<&dyn FinalityProofProvider<B>>
 	) -> CustomMessageOutcome<B> {
 		match message {
 			GenericMessage::Status(s) => self.on_status_message(network_out, who, s),
@@ -1399,7 +1399,7 @@ impl<B: BlockT, S: NetworkSpecialization<B>, H: ExHashT> Protocol<B, S, H> {
 		network_out: &mut dyn NetworkOut<B>,
 		who: PeerId,
 		request: message::FinalityProofRequest<B::Hash>,
-		finality_proof_provider: Option<&FinalityProofProvider<B>>
+		finality_proof_provider: Option<&dyn FinalityProofProvider<B>>
 	) {
 		trace!(target: "sync", "Finality proof request from {} for {}", who, request.block);
 		let finality_proof = finality_proof_provider.as_ref()
diff --git a/substrate/core/network/src/service.rs b/substrate/core/network/src/service.rs
index c7a32d472f..88c13b4806 100644
--- a/substrate/core/network/src/service.rs
+++ b/substrate/core/network/src/service.rs
@@ -358,7 +358,7 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>> NetworkService<B, S> {
 
 	/// Execute a closure with the chain-specific network specialization.
 	pub fn with_spec<F>(&self, f: F)
-		where F: FnOnce(&mut S, &mut Context<B>) + Send + 'static
+		where F: FnOnce(&mut S, &mut dyn Context<B>) + Send + 'static
 	{
 		let _ = self
 			.protocol_sender
@@ -367,7 +367,7 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>> NetworkService<B, S> {
 
 	/// Execute a closure with the consensus gossip.
 	pub fn with_gossip<F>(&self, f: F)
-		where F: FnOnce(&mut ConsensusGossip<B>, &mut Context<B>) + Send + 'static
+		where F: FnOnce(&mut ConsensusGossip<B>, &mut dyn Context<B>) + Send + 'static
 	{
 		let _ = self
 			.protocol_sender
@@ -489,9 +489,9 @@ pub enum ProtocolMsg<B: BlockT, S: NetworkSpecialization<B>> {
 	/// A block has been finalized (sent by the client).
 	BlockFinalized(B::Hash, B::Header),
 	/// Execute a closure with the chain-specific network specialization.
-	ExecuteWithSpec(Box<SpecTask<B, S> + Send + 'static>),
+	ExecuteWithSpec(Box<dyn SpecTask<B, S> + Send + 'static>),
 	/// Execute a closure with the consensus gossip.
-	ExecuteWithGossip(Box<GossipTask<B> + Send + 'static>),
+	ExecuteWithGossip(Box<dyn GossipTask<B> + Send + 'static>),
 	/// Incoming gossip consensus message.
 	GossipConsensusMessage(B::Hash, ConsensusEngineId, Vec<u8>, GossipMessageRecipient),
 	/// Tell protocol to perform regular maintenance.
@@ -504,22 +504,22 @@ pub enum ProtocolMsg<B: BlockT, S: NetworkSpecialization<B>> {
 
 /// A task, consisting of a user-provided closure, to be executed on the Protocol thread.
 pub trait SpecTask<B: BlockT, S: NetworkSpecialization<B>> {
-	fn call_box(self: Box<Self>, spec: &mut S, context: &mut Context<B>);
+	fn call_box(self: Box<Self>, spec: &mut S, context: &mut dyn Context<B>);
 }
 
-impl<B: BlockT, S: NetworkSpecialization<B>, F: FnOnce(&mut S, &mut Context<B>)> SpecTask<B, S> for F {
-	fn call_box(self: Box<F>, spec: &mut S, context: &mut Context<B>) {
+impl<B: BlockT, S: NetworkSpecialization<B>, F: FnOnce(&mut S, &mut dyn Context<B>)> SpecTask<B, S> for F {
+	fn call_box(self: Box<F>, spec: &mut S, context: &mut dyn Context<B>) {
 		(*self)(spec, context)
 	}
 }
 
 /// A task, consisting of a user-provided closure, to be executed on the Protocol thread.
 pub trait GossipTask<B: BlockT> {
-	fn call_box(self: Box<Self>, gossip: &mut ConsensusGossip<B>, context: &mut Context<B>);
+	fn call_box(self: Box<Self>, gossip: &mut ConsensusGossip<B>, context: &mut dyn Context<B>);
 }
 
-impl<B: BlockT, F: FnOnce(&mut ConsensusGossip<B>, &mut Context<B>)> GossipTask<B> for F {
-	fn call_box(self: Box<F>, gossip: &mut ConsensusGossip<B>, context: &mut Context<B>) {
+impl<B: BlockT, F: FnOnce(&mut ConsensusGossip<B>, &mut dyn Context<B>)> GossipTask<B> for F {
+	fn call_box(self: Box<F>, gossip: &mut ConsensusGossip<B>, context: &mut dyn Context<B>) {
 		(*self)(gossip, context)
 	}
 }
@@ -535,9 +535,9 @@ pub struct NetworkWorker<B: BlockT + 'static, S: NetworkSpecialization<B>, H: Ex
 	service: Arc<NetworkService<B, S>>,
 	network_service: Arc<Mutex<Libp2pNetService<Message<B>>>>,
 	peers: Arc<RwLock<HashMap<PeerId, ConnectedPeer<B>>>>,
-	import_queue: Box<ImportQueue<B>>,
+	import_queue: Box<dyn ImportQueue<B>>,
 	transaction_pool: Arc<dyn TransactionPool<H, B>>,
-	finality_proof_provider: Option<Arc<FinalityProofProvider<B>>>,
+	finality_proof_provider: Option<Arc<dyn FinalityProofProvider<B>>>,
 	network_port: mpsc::UnboundedReceiver<NetworkMsg<B>>,
 	protocol_rx: mpsc::UnboundedReceiver<ProtocolMsg<B, S>>,
 	status_sinks: Arc<Mutex<Vec<mpsc::UnboundedSender<ProtocolStatus<B>>>>>,
diff --git a/substrate/core/network/src/specialization.rs b/substrate/core/network/src/specialization.rs
index 2778146b52..772a1bcbe1 100644
--- a/substrate/core/network/src/specialization.rs
+++ b/substrate/core/network/src/specialization.rs
@@ -25,15 +25,15 @@ pub trait NetworkSpecialization<B: BlockT>: Send + Sync + 'static {
 	fn status(&self) -> Vec<u8>;
 
 	/// Called when a peer successfully handshakes.
-	fn on_connect(&mut self, ctx: &mut Context<B>, who: PeerId, status: crate::message::Status<B>);
+	fn on_connect(&mut self, ctx: &mut dyn Context<B>, who: PeerId, status: crate::message::Status<B>);
 
 	/// Called when a peer is disconnected. If the peer ID is unknown, it should be ignored.
-	fn on_disconnect(&mut self, ctx: &mut Context<B>, who: PeerId);
+	fn on_disconnect(&mut self, ctx: &mut dyn Context<B>, who: PeerId);
 
 	/// Called when a network-specific message arrives.
 	fn on_message(
 		&mut self,
-		ctx: &mut Context<B>,
+		ctx: &mut dyn Context<B>,
 		who: PeerId,
 		message: &mut Option<crate::message::Message<B>>
 	);
@@ -43,11 +43,11 @@ pub trait NetworkSpecialization<B: BlockT>: Send + Sync + 'static {
 	fn on_abort(&mut self) { }
 
 	/// Called periodically to maintain peers and handle timeouts.
-	fn maintain_peers(&mut self, _ctx: &mut Context<B>) { }
+	fn maintain_peers(&mut self, _ctx: &mut dyn Context<B>) { }
 
 	/// Called when a block is _imported_ at the head of the chain (not during major sync).
 	/// Not guaranteed to be called for every block, but will be most of the after major sync.
-	fn on_block_imported(&mut self, _ctx: &mut Context<B>, _hash: B::Hash, _header: &B::Header) { }
+	fn on_block_imported(&mut self, _ctx: &mut dyn Context<B>, _hash: B::Hash, _header: &B::Header) { }
 }
 
 /// Context for a network-specific handler.
diff --git a/substrate/core/network/src/sync.rs b/substrate/core/network/src/sync.rs
index 27a412ca0e..9b327c1a20 100644
--- a/substrate/core/network/src/sync.rs
+++ b/substrate/core/network/src/sync.rs
@@ -72,7 +72,7 @@ const GENESIS_MISMATCH_REPUTATION_CHANGE: i32 = i32::min_value() + 1;
 /// Context for a network-specific handler.
 pub trait Context<B: BlockT> {
 	/// Get a reference to the client.
-	fn client(&self) -> &crate::chain::Client<B>;
+	fn client(&self) -> &dyn crate::chain::Client<B>;
 
 	/// Adjusts the reputation of the peer. Use this to point out that a peer has been malign or
 	/// irresponsible or appeared lazy.
@@ -131,7 +131,7 @@ pub(crate) enum PeerSyncState<B: BlockT> {
 
 /// Relay chain sync strategy.
 pub struct ChainSync<B: BlockT> {
-	genesis_hash: B::Hash,
+	_genesis_hash: B::Hash,
 	peers: HashMap<PeerId, PeerSync<B>>,
 	blocks: BlockCollection<B>,
 	best_queued_number: NumberFor<B>,
@@ -191,7 +191,7 @@ impl<B: BlockT> ChainSync<B> {
 		}
 
 		ChainSync {
-			genesis_hash: info.chain.genesis_hash,
+			_genesis_hash: info.chain.genesis_hash,
 			peers: HashMap::new(),
 			blocks: BlockCollection::new(),
 			best_queued_hash: info.best_queued_hash.unwrap_or(info.chain.best_hash),
@@ -230,14 +230,14 @@ impl<B: BlockT> ChainSync<B> {
 		let best_seen = self.best_seen_block();
 		let state = self.state(&best_seen);
 		Status {
-			state: state,
+			state,
 			best_seen_block: best_seen,
 			num_peers: self.peers.len() as u32,
 		}
 	}
 
 	/// Handle new connected peer. Call this method whenever we connect to a new peer.
-	pub(crate) fn new_peer(&mut self, protocol: &mut Context<B>, who: PeerId) {
+	pub(crate) fn new_peer(&mut self, protocol: &mut dyn Context<B>, who: PeerId) {
 		if let Some(info) = protocol.peer_info(&who) {
 			// there's nothing sync can get from the node that has no blockchain data
 			// (the opposite is not true, but all requests are served at protocol level)
@@ -366,7 +366,7 @@ impl<B: BlockT> ChainSync<B> {
 	#[must_use]
 	pub(crate) fn on_block_data(
 		&mut self,
-		protocol: &mut Context<B>,
+		protocol: &mut dyn Context<B>,
 		who: PeerId,
 		request: message::BlockRequest<B>,
 		response: message::BlockResponse<B>
@@ -483,7 +483,7 @@ impl<B: BlockT> ChainSync<B> {
 	#[must_use]
 	pub(crate) fn on_block_justification_data(
 		&mut self,
-		protocol: &mut Context<B>,
+		protocol: &mut dyn Context<B>,
 		who: PeerId,
 		_request: message::BlockRequest<B>,
 		response: message::BlockResponse<B>,
@@ -528,7 +528,7 @@ impl<B: BlockT> ChainSync<B> {
 	/// Handle new finality proof data.
 	pub(crate) fn on_block_finality_proof_data(
 		&mut self,
-		protocol: &mut Context<B>,
+		protocol: &mut dyn Context<B>,
 		who: PeerId,
 		response: message::FinalityProofResponse<B::Hash>,
 	) -> Option<(PeerId, B::Hash, NumberFor<B>, Vec<u8>)> {
@@ -573,7 +573,7 @@ impl<B: BlockT> ChainSync<B> {
 	}
 
 	/// Maintain the sync process (download new blocks, fetch justifications).
-	pub fn maintain_sync(&mut self, protocol: &mut Context<B>) {
+	pub fn maintain_sync(&mut self, protocol: &mut dyn Context<B>) {
 		let peers: Vec<PeerId> = self.peers.keys().map(|p| p.clone()).collect();
 		for peer in peers {
 			self.download_new(protocol, peer);
@@ -583,7 +583,7 @@ impl<B: BlockT> ChainSync<B> {
 
 	/// Called periodically to perform any time-based actions. Must be called at a regular
 	/// interval.
-	pub fn tick(&mut self, protocol: &mut Context<B>) {
+	pub fn tick(&mut self, protocol: &mut dyn Context<B>) {
 		self.extra_requests.dispatch(&mut self.peers, protocol);
 	}
 
@@ -591,7 +591,7 @@ impl<B: BlockT> ChainSync<B> {
 	///
 	/// Uses `protocol` to queue a new justification request and tries to dispatch all pending
 	/// requests.
-	pub fn request_justification(&mut self, hash: &B::Hash, number: NumberFor<B>, protocol: &mut Context<B>) {
+	pub fn request_justification(&mut self, hash: &B::Hash, number: NumberFor<B>, protocol: &mut dyn Context<B>) {
 		self.extra_requests.justifications().queue_request(
 			(*hash, number),
 			|base, block| protocol.client().is_descendent_of(base, block),
@@ -620,7 +620,7 @@ impl<B: BlockT> ChainSync<B> {
 	/// Request a finality proof for the given block.
 	///
 	/// Queues a new finality proof request and tries to dispatch all pending requests.
-	pub fn request_finality_proof(&mut self, hash: &B::Hash, number: NumberFor<B>, protocol: &mut Context<B>) {
+	pub fn request_finality_proof(&mut self, hash: &B::Hash, number: NumberFor<B>, protocol: &mut dyn Context<B>) {
 		self.extra_requests.finality_proofs().queue_request(
 			(*hash, number),
 			|base, block| protocol.client().is_descendent_of(base, block),
@@ -647,7 +647,7 @@ impl<B: BlockT> ChainSync<B> {
 	}
 
 	/// Notify about finalization of the given block.
-	pub fn on_block_finalized(&mut self, hash: &B::Hash, number: NumberFor<B>, protocol: &mut Context<B>) {
+	pub fn on_block_finalized(&mut self, hash: &B::Hash, number: NumberFor<B>, protocol: &mut dyn Context<B>) {
 		if let Err(err) = self.extra_requests.on_block_finalized(
 			hash,
 			number,
@@ -699,7 +699,7 @@ impl<B: BlockT> ChainSync<B> {
 	#[must_use]
 	pub(crate) fn on_block_announce(
 		&mut self,
-		protocol: &mut Context<B>,
+		protocol: &mut dyn Context<B>,
 		who: PeerId,
 		hash: B::Hash,
 		header: &B::Header,
@@ -812,12 +812,12 @@ impl<B: BlockT> ChainSync<B> {
 		self.peers.iter().any(|(_, p)| p.state == PeerSyncState::DownloadingStale(*hash))
 	}
 
-	fn is_known(&self, protocol: &mut Context<B>, hash: &B::Hash) -> bool {
+	fn is_known(&self, protocol: &mut dyn Context<B>, hash: &B::Hash) -> bool {
 		block_status(&*protocol.client(), &self.queue_blocks, *hash).ok().map_or(false, |s| s != BlockStatus::Unknown)
 	}
 
 	/// Call when a peer has disconnected.
-	pub(crate) fn peer_disconnected(&mut self, protocol: &mut Context<B>, who: PeerId) {
+	pub(crate) fn peer_disconnected(&mut self, protocol: &mut dyn Context<B>, who: PeerId) {
 		self.blocks.clear_peer_download(&who);
 		self.peers.remove(&who);
 		self.extra_requests.peer_disconnected(who);
@@ -825,7 +825,7 @@ impl<B: BlockT> ChainSync<B> {
 	}
 
 	/// Restart the sync process.
-	pub(crate) fn restart(&mut self, protocol: &mut Context<B>) {
+	pub(crate) fn restart(&mut self, protocol: &mut dyn Context<B>) {
 		self.queue_blocks.clear();
 		self.best_importing_number = Zero::zero();
 		self.blocks.clear();
@@ -886,7 +886,7 @@ impl<B: BlockT> ChainSync<B> {
 	}
 
 	// Issue a request for a peer to download new blocks, if any are available.
-	fn download_new(&mut self, protocol: &mut Context<B>, who: PeerId) {
+	fn download_new(&mut self, protocol: &mut dyn Context<B>, who: PeerId) {
 		if let Some((_, request)) = self.select_new_blocks(who.clone()) {
 			protocol.send_block_request(who, request);
 		}
@@ -942,7 +942,7 @@ impl<B: BlockT> ChainSync<B> {
 		}
 	}
 
-	fn request_ancestry(protocol: &mut Context<B>, who: PeerId, block: NumberFor<B>) {
+	fn request_ancestry(protocol: &mut dyn Context<B>, who: PeerId, block: NumberFor<B>) {
 		trace!(target: "sync", "Requesting ancestry block #{} from {}", block, who);
 		let request = message::generic::BlockRequest {
 			id: 0,
@@ -958,7 +958,7 @@ impl<B: BlockT> ChainSync<B> {
 
 /// Get block status, taking into account import queue.
 fn block_status<B: BlockT>(
-	chain: &crate::chain::Client<B>,
+	chain: &dyn crate::chain::Client<B>,
 	queue_blocks: &HashSet<B::Hash>,
 	hash: B::Hash) -> Result<BlockStatus, ClientError>
 {
diff --git a/substrate/core/network/src/sync/extra_requests.rs b/substrate/core/network/src/sync/extra_requests.rs
index 3ebf2b2509..ff8323166b 100644
--- a/substrate/core/network/src/sync/extra_requests.rs
+++ b/substrate/core/network/src/sync/extra_requests.rs
@@ -39,7 +39,7 @@ pub(crate) trait ExtraRequestsEssence<B: BlockT> {
 	/// Name of request type to display in logs.
 	fn type_name(&self) -> &'static str;
 	/// Send network message corresponding to the request.
-	fn send_network_request(&self, protocol: &mut Context<B>, peer: PeerId, request: ExtraRequest<B>);
+	fn send_network_request(&self, protocol: &mut dyn Context<B>, peer: PeerId, request: ExtraRequest<B>);
 	/// Create peer state for peer that is downloading extra data.
 	fn peer_downloading_state(&self, block: B::Hash) -> PeerSyncState<B>;
 }
@@ -69,7 +69,7 @@ impl<B: BlockT> ExtraRequestsAggregator<B> {
 	}
 
 	/// Dispatches all possible pending requests to the given peers.
-	pub(crate) fn dispatch(&mut self, peers: &mut HashMap<PeerId, PeerSync<B>>, protocol: &mut Context<B>) {
+	pub(crate) fn dispatch(&mut self, peers: &mut HashMap<PeerId, PeerSync<B>>, protocol: &mut dyn Context<B>) {
 		self.justifications.dispatch(peers, protocol);
 		self.finality_proofs.dispatch(peers, protocol);
 	}
@@ -132,7 +132,7 @@ impl<B: BlockT, Essence: ExtraRequestsEssence<B>> ExtraRequests<B, Essence> {
 	/// extra request for block #10 to a peer at block #2), and we also
 	/// throttle requests to the same peer if a previous justification request
 	/// yielded no results.
-	pub(crate) fn dispatch(&mut self, peers: &mut HashMap<PeerId, PeerSync<B>>, protocol: &mut Context<B>) {
+	pub(crate) fn dispatch(&mut self, peers: &mut HashMap<PeerId, PeerSync<B>>, protocol: &mut dyn Context<B>) {
 		if self.pending_requests.is_empty() {
 			return;
 		}
@@ -373,7 +373,7 @@ impl<B: BlockT> ExtraRequestsEssence<B> for JustificationsRequestsEssence {
 		"justification"
 	}
 
-	fn send_network_request(&self, protocol: &mut Context<B>, peer: PeerId, request: ExtraRequest<B>) {
+	fn send_network_request(&self, protocol: &mut dyn Context<B>, peer: PeerId, request: ExtraRequest<B>) {
 		protocol.send_block_request(peer, message::generic::BlockRequest {
 			id: 0,
 			fields: message::BlockAttributes::JUSTIFICATION,
@@ -398,7 +398,7 @@ impl<B: BlockT> ExtraRequestsEssence<B> for FinalityProofRequestsEssence<B> {
 		"finality proof"
 	}
 
-	fn send_network_request(&self, protocol: &mut Context<B>, peer: PeerId, request: ExtraRequest<B>) {
+	fn send_network_request(&self, protocol: &mut dyn Context<B>, peer: PeerId, request: ExtraRequest<B>) {
 		protocol.send_finality_proof_request(peer, message::generic::FinalityProofRequest {
 			id: 0,
 			block: request.0,
diff --git a/substrate/core/network/src/test/mod.rs b/substrate/core/network/src/test/mod.rs
index b47cef11ac..b9703d71e0 100644
--- a/substrate/core/network/src/test/mod.rs
+++ b/substrate/core/network/src/test/mod.rs
@@ -103,22 +103,19 @@ impl NetworkSpecialization<Block> for DummySpecialization {
 
 	fn on_connect(
 		&mut self,
-		_ctx: &mut SpecializationContext<Block>,
+		_ctx: &mut dyn SpecializationContext<Block>,
 		_peer_id: PeerId,
 		_status: crate::message::Status<Block>
-	) {
-	}
+	) {}
 
-	fn on_disconnect(&mut self, _ctx: &mut SpecializationContext<Block>, _peer_id: PeerId) {
-	}
+	fn on_disconnect(&mut self, _ctx: &mut dyn SpecializationContext<Block>, _peer_id: PeerId) {}
 
 	fn on_message(
 		&mut self,
-		_ctx: &mut SpecializationContext<Block>,
+		_ctx: &mut dyn SpecializationContext<Block>,
 		_peer_id: PeerId,
 		_message: &mut Option<crate::message::Message<Block>>,
-	) {
-	}
+	) {}
 }
 
 pub type PeersFullClient =
@@ -292,7 +289,7 @@ pub struct Peer<D, S: NetworkSpecialization<Block>> {
 	finalized_hash: Mutex<Option<H256>>,
 }
 
-type MessageFilter = Fn(&NetworkMsg<Block>) -> bool;
+type MessageFilter = dyn Fn(&NetworkMsg<Block>) -> bool;
 
 pub enum FromNetworkMsg<B: BlockT> {
 	/// A peer connected, with debug info.
@@ -605,7 +602,7 @@ impl<D, S: NetworkSpecialization<Block>> Peer<D, S> {
 
 	/// Execute a closure with the consensus gossip.
 	pub fn with_gossip<F>(&self, f: F)
-		where F: FnOnce(&mut ConsensusGossip<Block>, &mut Context<Block>) + Send + 'static
+		where F: FnOnce(&mut ConsensusGossip<Block>, &mut dyn Context<Block>) + Send + 'static
 	{
 		self.net_proto_channel.send_from_client(ProtocolMsg::ExecuteWithGossip(Box::new(f)));
 	}
@@ -767,7 +764,7 @@ pub trait TestNetFactory: Sized {
 	}
 
 	/// Get finality proof provider (if supported).
-	fn make_finality_proof_provider(&self, _client: PeersClient) -> Option<Arc<FinalityProofProvider<Block>>> {
+	fn make_finality_proof_provider(&self, _client: PeersClient) -> Option<Arc<dyn FinalityProofProvider<Block>>> {
 		None
 	}
 
@@ -799,7 +796,7 @@ pub trait TestNetFactory: Sized {
 		protocol_status: Arc<RwLock<ProtocolStatus<Block>>>,
 		import_queue: Box<BasicQueue<Block>>,
 		tx_pool: EmptyTransactionPool,
-		finality_proof_provider: Option<Arc<FinalityProofProvider<Block>>>,
+		finality_proof_provider: Option<Arc<dyn FinalityProofProvider<Block>>>,
 		mut protocol: Protocol<Block, Self::Specialization, Hash>,
 		network_sender: mpsc::UnboundedSender<NetworkMsg<Block>>,
 		mut network_to_protocol_rx: mpsc::UnboundedReceiver<FromNetworkMsg<Block>>,
diff --git a/substrate/core/offchain/src/lib.rs b/substrate/core/offchain/src/lib.rs
index 376f41b445..081ae61a5b 100644
--- a/substrate/core/offchain/src/lib.rs
+++ b/substrate/core/offchain/src/lib.rs
@@ -91,7 +91,7 @@ impl<C, Block> OffchainWorkers<C, Block> where
 	{
 		let runtime = self.client.runtime_api();
 		let at = BlockId::number(*number);
-		let has_api = runtime.has_api::<OffchainWorkerApi<Block>>(&at);
+		let has_api = runtime.has_api::<dyn OffchainWorkerApi<Block>>(&at);
 		debug!("Checking offchain workers at {:?}: {:?}", at, has_api);
 
 		if has_api.unwrap_or(false) {
diff --git a/substrate/core/primitives/src/hexdisplay.rs b/substrate/core/primitives/src/hexdisplay.rs
index d748208d0e..cd2b6c18cb 100644
--- a/substrate/core/primitives/src/hexdisplay.rs
+++ b/substrate/core/primitives/src/hexdisplay.rs
@@ -21,7 +21,7 @@ pub struct HexDisplay<'a>(&'a [u8]);
 
 impl<'a> HexDisplay<'a> {
 	/// Create new instance that will display `d` as a hex string when displayed.
-	pub fn from(d: &'a AsBytesRef) -> Self { HexDisplay(d.as_bytes_ref()) }
+	pub fn from(d: &'a dyn AsBytesRef) -> Self { HexDisplay(d.as_bytes_ref()) }
 }
 
 impl<'a> ::core::fmt::Display for HexDisplay<'a> {
@@ -79,7 +79,7 @@ pub fn ascii_format(asciish: &[u8]) -> String {
 	let mut latch = false;
 	for c in asciish {
 		match (latch, *c) {
-			(false, 32...127) => r.push(*c as char),
+			(false, 32..=127) => r.push(*c as char),
 			_ => {
 				if !latch {
 					r.push('#');
diff --git a/substrate/core/primitives/src/lib.rs b/substrate/core/primitives/src/lib.rs
index 69b9f1a960..7c0fd324fe 100644
--- a/substrate/core/primitives/src/lib.rs
+++ b/substrate/core/primitives/src/lib.rs
@@ -86,7 +86,7 @@ pub enum ExecutionContext {
 	/// Context used for block construction.
 	BlockConstruction,
 	/// Offchain worker context.
-	OffchainWorker(Box<offchain::Externalities>),
+	OffchainWorker(Box<dyn offchain::Externalities>),
 	/// Context used for other calls.
 	Other,
 }
diff --git a/substrate/core/primitives/src/offchain.rs b/substrate/core/primitives/src/offchain.rs
index 764837d7b4..7d54c9d61e 100644
--- a/substrate/core/primitives/src/offchain.rs
+++ b/substrate/core/primitives/src/offchain.rs
@@ -35,8 +35,8 @@ impl TryFrom<u32> for CryptoKind {
 
 	fn try_from(kind: u32) -> Result<Self, Self::Error> {
 		match kind {
-			e if e == CryptoKind::Sr25519 as u8 as u32 => Ok(CryptoKind::Sr25519),
-			e if e == CryptoKind::Ed25519 as u8 as u32 => Ok(CryptoKind::Ed25519),
+			e if e == u32::from(CryptoKind::Sr25519 as u8) => Ok(CryptoKind::Sr25519),
+			e if e == u32::from(CryptoKind::Ed25519 as u8) => Ok(CryptoKind::Ed25519),
 			_ => Err(())
 		}
 	}
@@ -103,7 +103,7 @@ impl From<HttpRequestStatus> for u32 {
 			HttpRequestStatus::Unknown => 0,
 			HttpRequestStatus::DeadlineReached => 10,
 			HttpRequestStatus::Timeout => 20,
-			HttpRequestStatus::Finished(code) => code as u32,
+			HttpRequestStatus::Finished(code) => u32::from(code),
 		}
 	}
 }
@@ -116,7 +116,7 @@ impl TryFrom<u32> for HttpRequestStatus {
 			0 => Ok(HttpRequestStatus::Unknown),
 			10 => Ok(HttpRequestStatus::DeadlineReached),
 			20 => Ok(HttpRequestStatus::Timeout),
-			100...999 => Ok(HttpRequestStatus::Finished(status as u16)),
+			100..=999 => u16::try_from(status).map(HttpRequestStatus::Finished).map_err(|_| ()),
 			_ => Err(()),
 		}
 	}
diff --git a/substrate/core/primitives/src/sr25519.rs b/substrate/core/primitives/src/sr25519.rs
index 8f309ec030..876dcb7078 100644
--- a/substrate/core/primitives/src/sr25519.rs
+++ b/substrate/core/primitives/src/sr25519.rs
@@ -204,16 +204,16 @@ impl From<schnorrkel::Signature> for Signature {
 }
 
 #[cfg(feature = "std")]
-impl ::std::fmt::Debug for Signature {
+impl std::fmt::Debug for Signature {
 	fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
 		write!(f, "{}", crate::hexdisplay::HexDisplay::from(&self.0))
 	}
 }
 
 #[cfg(feature = "std")]
-impl ::std::hash::Hash for Signature {
-	fn hash<H: ::std::hash::Hasher>(&self, state: &mut H) {
-		::std::hash::Hash::hash(&self.0[..], state);
+impl std::hash::Hash for Signature {
+	fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+		std::hash::Hash::hash(&self.0[..], state);
 	}
 }
 
@@ -304,15 +304,13 @@ impl Public {
 
 	/// Return a `Vec<u8>` filled with raw data.
 	#[cfg(feature = "std")]
-	pub fn to_raw_vec(self) -> Vec<u8> {
-		let r: &[u8; 32] = self.as_ref();
-		r.to_vec()
+	pub fn into_raw_vec(self) -> Vec<u8> {
+		self.0.to_vec()
 	}
 
 	/// Return a slice filled with raw data.
 	pub fn as_slice(&self) -> &[u8] {
-		let r: &[u8; 32] = self.as_ref();
-		&r[..]
+		&self.0
 	}
 
 	/// Return a slice filled with raw data.
@@ -637,7 +635,7 @@ mod test {
 	#[test]
 	fn verify_from_wasm_works() {
 		// The values in this test case are compared to the output of `node-test.js` in schnorrkel-js.
-		// 
+		//
 		// This is to make sure that the wasm library is compatible.
 		let pk = Pair::from_seed(hex!("0000000000000000000000000000000000000000000000000000000000000000"));
 		let public = pk.public();
diff --git a/substrate/core/rpc/src/author/error.rs b/substrate/core/rpc/src/author/error.rs
index 5955108249..008a70b674 100644
--- a/substrate/core/rpc/src/author/error.rs
+++ b/substrate/core/rpc/src/author/error.rs
@@ -34,7 +34,7 @@ pub enum Error {
 	Pool(txpool::error::Error),
 	/// Verification error
 	#[display(fmt="Extrinsic verification error: {}", "_0.description()")]
-	Verification(Box<::std::error::Error + Send>),
+	Verification(Box<dyn std::error::Error + Send>),
 	/// Incorrect extrinsic format.
 	#[display(fmt="Invalid extrinsic format")]
 	BadFormat,
diff --git a/substrate/core/rpc/src/system/mod.rs b/substrate/core/rpc/src/system/mod.rs
index 8aac02b77d..d6f2b75515 100644
--- a/substrate/core/rpc/src/system/mod.rs
+++ b/substrate/core/rpc/src/system/mod.rs
@@ -74,7 +74,7 @@ pub trait SystemApi<Hash, Number> {
 /// System API implementation
 pub struct System<B: traits::Block> {
 	info: SystemInfo,
-	sync: Arc<network::SyncProvider<B>>,
+	sync: Arc<dyn network::SyncProvider<B>>,
 	should_have_peers: bool,
 }
 
@@ -82,7 +82,7 @@ impl<B: traits::Block> System<B> {
 	/// Creates new `System` given the `SystemInfo`.
 	pub fn new(
 		info: SystemInfo,
-		sync: Arc<network::SyncProvider<B>>,
+		sync: Arc<dyn network::SyncProvider<B>>,
 		should_have_peers: bool,
 	) -> Self {
 		System {
diff --git a/substrate/core/service/src/chain_ops.rs b/substrate/core/service/src/chain_ops.rs
index 3be3b9b17a..83f103ec8f 100644
--- a/substrate/core/service/src/chain_ops.rs
+++ b/substrate/core/service/src/chain_ops.rs
@@ -151,7 +151,7 @@ pub fn import_blocks<F, E, R>(
 			let (header, extrinsics) = signed.block.deconstruct();
 			let hash = header.hash();
 			let block  = message::BlockData::<F::Block> {
-				hash: hash,
+				hash,
 				justification: signed.justification,
 				header: Some(header),
 				body: Some(extrinsics),
diff --git a/substrate/core/service/src/components.rs b/substrate/core/service/src/components.rs
index 3876279cc7..a314588d0a 100644
--- a/substrate/core/service/src/components.rs
+++ b/substrate/core/service/src/components.rs
@@ -139,7 +139,7 @@ pub trait StartRPC<C: Components> {
 
 	fn start_rpc(
 		client: Arc<ComponentClient<C>>,
-		network: Arc<network::SyncProvider<ComponentBlock<C>>>,
+		network: Arc<dyn network::SyncProvider<ComponentBlock<C>>>,
 		should_have_peers: bool,
 		system_info: SystemInfo,
 		rpc_http: Option<SocketAddr>,
@@ -159,7 +159,7 @@ impl<C: Components> StartRPC<Self> for C where
 
 	fn start_rpc(
 		client: Arc<ComponentClient<C>>,
-		network: Arc<network::SyncProvider<ComponentBlock<C>>>,
+		network: Arc<dyn network::SyncProvider<ComponentBlock<C>>>,
 		should_have_peers: bool,
 		rpc_system_info: SystemInfo,
 		rpc_http: Option<SocketAddr>,
@@ -339,7 +339,7 @@ pub trait ServiceFactory: 'static + Sized {
 	/// Build finality proof provider for serving network requests on full node.
 	fn build_finality_proof_provider(
 		client: Arc<FullClient<Self>>
-	) -> Result<Option<Arc<FinalityProofProvider<Self::Block>>>, error::Error>;
+	) -> Result<Option<Arc<dyn FinalityProofProvider<Self::Block>>>, error::Error>;
 
 	/// Build the Fork Choice algorithm for full client
 	fn build_select_chain(
@@ -435,7 +435,7 @@ pub trait Components: Sized + 'static {
 	/// Finality proof provider for serving network requests.
 	fn build_finality_proof_provider(
 		client: Arc<ComponentClient<Self>>
-	) -> Result<Option<Arc<FinalityProofProvider<<Self::Factory as ServiceFactory>::Block>>>, error::Error>;
+	) -> Result<Option<Arc<dyn FinalityProofProvider<<Self::Factory as ServiceFactory>::Block>>>, error::Error>;
 
 	/// Build fork choice selector
 	fn build_select_chain(
@@ -536,7 +536,7 @@ impl<Factory: ServiceFactory> Components for FullComponents<Factory> {
 
 	fn build_finality_proof_provider(
 		client: Arc<ComponentClient<Self>>
-	) -> Result<Option<Arc<FinalityProofProvider<<Self::Factory as ServiceFactory>::Block>>>, error::Error> {
+	) -> Result<Option<Arc<dyn FinalityProofProvider<<Self::Factory as ServiceFactory>::Block>>>, error::Error> {
 		Factory::build_finality_proof_provider(client)
 	}
 }
@@ -619,7 +619,7 @@ impl<Factory: ServiceFactory> Components for LightComponents<Factory> {
 
 	fn build_finality_proof_provider(
 		_client: Arc<ComponentClient<Self>>
-	) -> Result<Option<Arc<FinalityProofProvider<<Self::Factory as ServiceFactory>::Block>>>, error::Error> {
+	) -> Result<Option<Arc<dyn FinalityProofProvider<<Self::Factory as ServiceFactory>::Block>>>, error::Error> {
 		Ok(None)
 	}
 	fn build_select_chain(
diff --git a/substrate/core/service/src/lib.rs b/substrate/core/service/src/lib.rs
index 0e16d2e7be..bc40d6008b 100644
--- a/substrate/core/service/src/lib.rs
+++ b/substrate/core/service/src/lib.rs
@@ -80,7 +80,7 @@ pub struct Service<Components: components::Components> {
 	signal: Option<Signal>,
 	/// Configuration of this Service
 	pub config: FactoryFullConfiguration<Components::Factory>,
-	_rpc: Box<::std::any::Any + Send + Sync>,
+	_rpc: Box<dyn std::any::Any + Send + Sync>,
 	_telemetry: Option<Arc<tel::Telemetry>>,
 	_offchain_workers: Option<Arc<offchain::OffchainWorkers<ComponentClient<Components>, ComponentBlock<Components>>>>,
 	_telemetry_on_connect_sinks: Arc<Mutex<Vec<mpsc::UnboundedSender<()>>>>,
@@ -104,7 +104,7 @@ pub type TelemetryOnConnectNotifications = mpsc::UnboundedReceiver<()>;
 /// Used to hook on telemetry connection established events.
 pub struct TelemetryOnConnect<'a> {
 	/// Handle to a future that will resolve on exit.
-	pub on_exit: Box<Future<Item=(), Error=()> + Send + 'static>,
+	pub on_exit: Box<dyn Future<Item=(), Error=()> + Send + 'static>,
 	/// Event stream.
 	pub telemetry_connection_sinks: TelemetryOnConnectNotifications,
 	/// Executor to which the hook is spawned.
diff --git a/substrate/core/sr-api-macros/src/lib.rs b/substrate/core/sr-api-macros/src/lib.rs
index c5f8941002..7399da0794 100644
--- a/substrate/core/sr-api-macros/src/lib.rs
+++ b/substrate/core/sr-api-macros/src/lib.rs
@@ -54,11 +54,11 @@ mod utils;
 /// # extern crate substrate_primitives;
 /// #
 /// # use runtime_primitives::traits::GetNodeBlockType;
-/// # use test_client::runtime::Block;
+/// # use test_client::runtime::{Block, Header};
 /// #
 /// # /// The declaration of the `Runtime` type and the implementation of the `GetNodeBlockType`
 /// # /// trait are done by the `construct_runtime!` macro in a real runtime.
-/// # struct Runtime {}
+/// # pub struct Runtime {}
 /// # impl GetNodeBlockType for Runtime {
 /// #     type NodeBlock = Block;
 /// # }
@@ -78,6 +78,15 @@ mod utils;
 ///
 /// /// All runtime api implementations need to be done in one call of the macro!
 /// impl_runtime_apis! {
+/// #   impl client::runtime_api::Core<Block> for Runtime {
+/// #       fn version() -> client::runtime_api::RuntimeVersion {
+/// #           unimplemented!()
+/// #       }
+/// #       fn execute_block(_block: Block) {}
+/// #       fn initialize_block(_header: &Header) {}
+/// #       fn authorities() -> Vec<runtime_primitives::traits::AuthorityIdFor<Block>> { unimplemented!() }
+/// #   }
+///
 ///     impl self::Balance<Block> for Runtime {
 ///         fn get_balance() -> u64 {
 ///             1
@@ -176,7 +185,7 @@ pub fn impl_runtime_apis(input: TokenStream) -> TokenStream {
 ///         ///
 ///         /// Is callable by `set_balance_before_version_2`.
 ///         #[changed_in(2)]
-///         fn set_balance(val: u8);
+///         fn set_balance(val: u16);
 ///         /// In version 2, we added this new function.
 ///         fn increase_balance(val: u64);
 ///     }
diff --git a/substrate/core/sr-api-macros/tests/decl_and_impl.rs b/substrate/core/sr-api-macros/tests/decl_and_impl.rs
index 51f95d51b1..44db8021d4 100644
--- a/substrate/core/sr-api-macros/tests/decl_and_impl.rs
+++ b/substrate/core/sr-api-macros/tests/decl_and_impl.rs
@@ -122,7 +122,7 @@ fn check_runtime_api_versions_contains<T: RuntimeApiInfo + ?Sized>() {
 
 #[test]
 fn check_runtime_api_versions() {
-	check_runtime_api_versions_contains::<Api<Block>>();
-	check_runtime_api_versions_contains::<ApiWithCustomVersion<Block>>();
-	check_runtime_api_versions_contains::<runtime_api::Core<Block>>();
+	check_runtime_api_versions_contains::<dyn Api<Block>>();
+	check_runtime_api_versions_contains::<dyn ApiWithCustomVersion<Block>>();
+	check_runtime_api_versions_contains::<dyn runtime_api::Core<Block>>();
 }
diff --git a/substrate/core/sr-io/with_std.rs b/substrate/core/sr-io/with_std.rs
index 01e7614de6..0ba833bd9f 100644
--- a/substrate/core/sr-io/with_std.rs
+++ b/substrate/core/sr-io/with_std.rs
@@ -251,7 +251,7 @@ impl HashingApi for () {
 	}
 }
 
-fn with_offchain<R>(f: impl FnOnce(&mut offchain::Externalities) -> R, msg: &'static str) -> R {
+fn with_offchain<R>(f: impl FnOnce(&mut dyn offchain::Externalities) -> R, msg: &'static str) -> R {
 	ext::with(|ext| ext
 		.offchain()
 		.map(|ext| f(ext))
@@ -395,7 +395,7 @@ impl Api for () {}
 /// Execute the given closure with global function available whose functionality routes into the
 /// externalities `ext`. Forwards the value that the closure returns.
 // NOTE: need a concrete hasher here due to limitations of the `environmental!` macro, otherwise a type param would have been fine I think.
-pub fn with_externalities<R, F: FnOnce() -> R>(ext: &mut Externalities<Blake2Hasher>, f: F) -> R {
+pub fn with_externalities<R, F: FnOnce() -> R>(ext: &mut dyn Externalities<Blake2Hasher>, f: F) -> R {
 	ext::using(ext, f)
 }
 
diff --git a/substrate/core/sr-primitives/src/generic/mod.rs b/substrate/core/sr-primitives/src/generic/mod.rs
index 3d7682407e..89c4291d79 100644
--- a/substrate/core/sr-primitives/src/generic/mod.rs
+++ b/substrate/core/sr-primitives/src/generic/mod.rs
@@ -44,8 +44,8 @@ use rstd::prelude::*;
 fn encode_with_vec_prefix<T: Encode, F: Fn(&mut Vec<u8>)>(encoder: F) -> Vec<u8> {
 	let size = ::rstd::mem::size_of::<T>();
 	let reserve = match size {
-		0...0b00111111 => 1,
-		0...0b00111111_11111111 => 2,
+		0..=0b00111111 => 1,
+		0..=0b00111111_11111111 => 2,
 		_ => 4,
 	};
 	let mut v = Vec::with_capacity(reserve + size);
diff --git a/substrate/core/state-machine/src/basic.rs b/substrate/core/state-machine/src/basic.rs
index 0eb0b84b27..e9939711f1 100644
--- a/substrate/core/state-machine/src/basic.rs
+++ b/substrate/core/state-machine/src/basic.rs
@@ -156,7 +156,7 @@ impl<H: Hasher> Externalities<H> for BasicExternalities where H::Out: Ord {
 		Ok(None)
 	}
 
-	fn offchain(&mut self) -> Option<&mut offchain::Externalities> {
+	fn offchain(&mut self) -> Option<&mut dyn offchain::Externalities> {
 		warn!("Call to non-existent out offchain externalities set.");
 		None
 	}
@@ -171,7 +171,7 @@ mod tests {
 	#[test]
 	fn commit_should_work() {
 		let mut ext = BasicExternalities::default();
-		let ext = &mut ext as &mut Externalities<Blake2Hasher>;
+		let ext = &mut ext as &mut dyn Externalities<Blake2Hasher>;
 		ext.set_storage(b"doe".to_vec(), b"reindeer".to_vec());
 		ext.set_storage(b"dog".to_vec(), b"puppy".to_vec());
 		ext.set_storage(b"dogglesworth".to_vec(), b"cat".to_vec());
@@ -182,7 +182,7 @@ mod tests {
 	#[test]
 	fn set_and_retrieve_code() {
 		let mut ext = BasicExternalities::default();
-		let ext = &mut ext as &mut Externalities<Blake2Hasher>;
+		let ext = &mut ext as &mut dyn Externalities<Blake2Hasher>;
 
 		let code = vec![1, 2, 3];
 		ext.set_storage(CODE.to_vec(), code.clone());
diff --git a/substrate/core/state-machine/src/changes_trie/mod.rs b/substrate/core/state-machine/src/changes_trie/mod.rs
index 15ea1b474f..7dc95fb5a7 100644
--- a/substrate/core/state-machine/src/changes_trie/mod.rs
+++ b/substrate/core/state-machine/src/changes_trie/mod.rs
@@ -112,7 +112,7 @@ pub trait Storage<H: Hasher, Number: BlockNumber>: RootsStorage<H, Number> {
 }
 
 /// Changes trie storage -> trie backend essence adapter.
-pub struct TrieBackendStorageAdapter<'a, H: Hasher, Number: BlockNumber>(pub &'a Storage<H, Number>);
+pub struct TrieBackendStorageAdapter<'a, H: Hasher, Number: BlockNumber>(pub &'a dyn Storage<H, Number>);
 
 impl<'a, H: Hasher, N: BlockNumber> crate::TrieBackendStorage<H> for TrieBackendStorageAdapter<'a, H, N> {
 	type Overlay = trie::MemoryDB<H>;
diff --git a/substrate/core/state-machine/src/ext.rs b/substrate/core/state-machine/src/ext.rs
index 6ec1ce77e6..5a0daeb348 100644
--- a/substrate/core/state-machine/src/ext.rs
+++ b/substrate/core/state-machine/src/ext.rs
@@ -343,7 +343,7 @@ where
 		Ok(root)
 	}
 
-	fn offchain(&mut self) -> Option<&mut offchain::Externalities> {
+	fn offchain(&mut self) -> Option<&mut dyn offchain::Externalities> {
 		self.offchain_externalities.as_mut().map(|x| &mut **x as _)
 	}
 }
diff --git a/substrate/core/state-machine/src/lib.rs b/substrate/core/state-machine/src/lib.rs
index 9f0e20ce01..93d70423d5 100644
--- a/substrate/core/state-machine/src/lib.rs
+++ b/substrate/core/state-machine/src/lib.rs
@@ -222,7 +222,7 @@ pub trait Externalities<H: Hasher> {
 	fn storage_changes_root(&mut self, parent: H::Out) -> Result<Option<H::Out>, ()> where H::Out: Ord;
 
 	/// Returns offchain externalities extension if present.
-	fn offchain(&mut self) -> Option<&mut offchain::Externalities>;
+	fn offchain(&mut self) -> Option<&mut dyn offchain::Externalities>;
 }
 
 /// An implementation of offchain extensions that should never be triggered.
@@ -502,7 +502,7 @@ impl<'a, H, N, B, T, O, Exec> StateMachine<'a, H, N, B, T, O, Exec> where
 	pub fn execute(
 		&mut self,
 		strategy: ExecutionStrategy,
-	) -> Result<(Vec<u8>, B::Transaction, Option<MemoryDB<H>>), Box<Error>> {
+	) -> Result<(Vec<u8>, B::Transaction, Option<MemoryDB<H>>), Box<dyn Error>> {
 		// We are not giving a native call and thus we are sure that the result can never be a native
 		// value.
 		self.execute_using_consensus_failure_handler::<_, NeverNativeValue, fn() -> _>(
@@ -613,7 +613,7 @@ impl<'a, H, N, B, T, O, Exec> StateMachine<'a, H, N, B, T, O, Exec> where
 		manager: ExecutionManager<Handler>,
 		compute_tx: bool,
 		mut native_call: Option<NC>,
-	) -> Result<(NativeOrEncoded<R>, Option<B::Transaction>, Option<MemoryDB<H>>), Box<Error>> where
+	) -> Result<(NativeOrEncoded<R>, Option<B::Transaction>, Option<MemoryDB<H>>), Box<dyn Error>> where
 		R: Decode + Encode + PartialEq,
 		NC: FnOnce() -> result::Result<R, &'static str> + UnwindSafe,
 		Handler: FnOnce(
@@ -674,7 +674,7 @@ pub fn prove_execution<B, H, Exec>(
 	exec: &Exec,
 	method: &str,
 	call_data: &[u8],
-) -> Result<(Vec<u8>, Vec<Vec<u8>>), Box<Error>>
+) -> Result<(Vec<u8>, Vec<Vec<u8>>), Box<dyn Error>>
 where
 	B: Backend<H>,
 	H: Hasher,
@@ -682,7 +682,7 @@ where
 	H::Out: Ord + 'static,
 {
 	let trie_backend = backend.as_trie_backend()
-		.ok_or_else(|| Box::new(ExecutionError::UnableToGenerateProof) as Box<Error>)?;
+		.ok_or_else(|| Box::new(ExecutionError::UnableToGenerateProof) as Box<dyn Error>)?;
 	prove_execution_on_trie_backend(trie_backend, overlay, exec, method, call_data)
 }
 
@@ -701,7 +701,7 @@ pub fn prove_execution_on_trie_backend<S, H, Exec>(
 	exec: &Exec,
 	method: &str,
 	call_data: &[u8],
-) -> Result<(Vec<u8>, Vec<Vec<u8>>), Box<Error>>
+) -> Result<(Vec<u8>, Vec<Vec<u8>>), Box<dyn Error>>
 where
 	S: trie_backend_essence::TrieBackendStorage<H>,
 	H: Hasher,
@@ -736,7 +736,7 @@ pub fn execution_proof_check<H, Exec>(
 	exec: &Exec,
 	method: &str,
 	call_data: &[u8],
-) -> Result<Vec<u8>, Box<Error>>
+) -> Result<Vec<u8>, Box<dyn Error>>
 where
 	H: Hasher,
 	Exec: CodeExecutor<H>,
@@ -753,7 +753,7 @@ pub fn execution_proof_check_on_trie_backend<H, Exec>(
 	exec: &Exec,
 	method: &str,
 	call_data: &[u8],
-) -> Result<Vec<u8>, Box<Error>>
+) -> Result<Vec<u8>, Box<dyn Error>>
 where
 	H: Hasher,
 	Exec: CodeExecutor<H>,
@@ -780,7 +780,7 @@ where
 pub fn prove_read<B, H>(
 	mut backend: B,
 	key: &[u8]
-) -> Result<(Option<Vec<u8>>, Vec<Vec<u8>>), Box<Error>>
+) -> Result<(Option<Vec<u8>>, Vec<Vec<u8>>), Box<dyn Error>>
 where
 	B: Backend<H>,
 	H: Hasher,
@@ -788,7 +788,7 @@ where
 {
 	let trie_backend = backend.as_trie_backend()
 		.ok_or_else(
-			||Box::new(ExecutionError::UnableToGenerateProof) as Box<Error>
+			||Box::new(ExecutionError::UnableToGenerateProof) as Box<dyn Error>
 		)?;
 	prove_read_on_trie_backend(trie_backend, key)
 }
@@ -798,14 +798,14 @@ pub fn prove_child_read<B, H>(
 	mut backend: B,
 	storage_key: &[u8],
 	key: &[u8],
-) -> Result<(Option<Vec<u8>>, Vec<Vec<u8>>), Box<Error>>
+) -> Result<(Option<Vec<u8>>, Vec<Vec<u8>>), Box<dyn Error>>
 where
 	B: Backend<H>,
 	H: Hasher,
 	H::Out: Ord
 {
 	let trie_backend = backend.as_trie_backend()
-		.ok_or_else(|| Box::new(ExecutionError::UnableToGenerateProof) as Box<Error>)?;
+		.ok_or_else(|| Box::new(ExecutionError::UnableToGenerateProof) as Box<dyn Error>)?;
 	prove_child_read_on_trie_backend(trie_backend, storage_key, key)
 }
 
@@ -814,14 +814,14 @@ where
 pub fn prove_read_on_trie_backend<S, H>(
 	trie_backend: &TrieBackend<S, H>,
 	key: &[u8]
-) -> Result<(Option<Vec<u8>>, Vec<Vec<u8>>), Box<Error>>
+) -> Result<(Option<Vec<u8>>, Vec<Vec<u8>>), Box<dyn Error>>
 where
 	S: trie_backend_essence::TrieBackendStorage<H>,
 	H: Hasher,
 	H::Out: Ord
 {
 	let proving_backend = proving_backend::ProvingBackend::<_, H>::new(trie_backend);
-	let result = proving_backend.storage(key).map_err(|e| Box::new(e) as Box<Error>)?;
+	let result = proving_backend.storage(key).map_err(|e| Box::new(e) as Box<dyn Error>)?;
 	Ok((result, proving_backend.extract_proof()))
 }
 
@@ -830,15 +830,14 @@ pub fn prove_child_read_on_trie_backend<S, H>(
 	trie_backend: &TrieBackend<S, H>,
 	storage_key: &[u8],
 	key: &[u8]
-) -> Result<(Option<Vec<u8>>, Vec<Vec<u8>>), Box<Error>>
+) -> Result<(Option<Vec<u8>>, Vec<Vec<u8>>), Box<dyn Error>>
 where
 	S: trie_backend_essence::TrieBackendStorage<H>,
 	H: Hasher,
 	H::Out: Ord
 {
 	let proving_backend = proving_backend::ProvingBackend::<_, H>::new(trie_backend);
-	let result = proving_backend.child_storage(storage_key, key)
-		.map_err(|e| Box::new(e) as Box<Error>)?;
+	let result = proving_backend.child_storage(storage_key, key).map_err(|e| Box::new(e) as Box<dyn Error>)?;
 	Ok((result, proving_backend.extract_proof()))
 }
 
@@ -847,7 +846,7 @@ pub fn read_proof_check<H>(
 	root: H::Out,
 	proof: Vec<Vec<u8>>,
 	key: &[u8],
-) -> Result<Option<Vec<u8>>, Box<Error>>
+) -> Result<Option<Vec<u8>>, Box<dyn Error>>
 where
 	H: Hasher,
 	H::Out: Ord
@@ -862,7 +861,7 @@ pub fn read_child_proof_check<H>(
 	proof: Vec<Vec<u8>>,
 	storage_key: &[u8],
 	key: &[u8],
-) -> Result<Option<Vec<u8>>, Box<Error>>
+) -> Result<Option<Vec<u8>>, Box<dyn Error>>
 where
 	H: Hasher,
 	H::Out: Ord
@@ -876,12 +875,12 @@ where
 pub fn read_proof_check_on_proving_backend<H>(
 	proving_backend: &TrieBackend<MemoryDB<H>, H>,
 	key: &[u8],
-) -> Result<Option<Vec<u8>>, Box<Error>>
+) -> Result<Option<Vec<u8>>, Box<dyn Error>>
 where
 	H: Hasher,
 	H::Out: Ord
 {
-	proving_backend.storage(key).map_err(|e| Box::new(e) as Box<Error>)
+	proving_backend.storage(key).map_err(|e| Box::new(e) as Box<dyn Error>)
 }
 
 /// Check child storage read proof on pre-created proving backend.
@@ -889,20 +888,24 @@ pub fn read_child_proof_check_on_proving_backend<H>(
 	proving_backend: &TrieBackend<MemoryDB<H>, H>,
 	storage_key: &[u8],
 	key: &[u8],
-) -> Result<Option<Vec<u8>>, Box<Error>>
+) -> Result<Option<Vec<u8>>, Box<dyn Error>>
 where
 	H: Hasher,
 	H::Out: Ord
 {
-	proving_backend.child_storage(storage_key, key).map_err(|e| Box::new(e) as Box<Error>)
+	proving_backend.child_storage(storage_key, key).map_err(|e| Box::new(e) as Box<dyn Error>)
 }
 
 /// Sets overlayed changes' changes trie configuration. Returns error if configuration
 /// differs from previous OR config decode has failed.
-pub(crate) fn set_changes_trie_config(overlay: &mut OverlayedChanges, config: Option<Vec<u8>>, final_check: bool) -> Result<(), Box<Error>> {
+pub(crate) fn set_changes_trie_config(
+	overlay: &mut OverlayedChanges,
+	config: Option<Vec<u8>>,
+	final_check: bool,
+) -> Result<(), Box<dyn Error>> {
 	let config = match config {
 		Some(v) => Some(Decode::decode(&mut &v[..])
-			.ok_or_else(|| Box::new("Failed to decode changes trie configuration".to_owned()) as Box<Error>)?),
+			.ok_or_else(|| Box::new("Failed to decode changes trie configuration".to_owned()) as Box<dyn Error>)?),
 		None => None,
 	};
 
@@ -920,16 +923,16 @@ pub(crate) fn set_changes_trie_config(overlay: &mut OverlayedChanges, config: Op
 
 /// Reads storage value from overlay or from the backend.
 fn try_read_overlay_value<H, B>(overlay: &OverlayedChanges, backend: &B, key: &[u8])
-	-> Result<Option<Vec<u8>>, Box<Error>>
+	-> Result<Option<Vec<u8>>, Box<dyn Error>>
 where
 	H: Hasher,
-
 	B: Backend<H>,
 {
 	match overlay.storage(key).map(|x| x.map(|x| x.to_vec())) {
 		Some(value) => Ok(value),
-		None => backend.storage(key)
-			.map_err(|err| Box::new(ExecutionError::Backend(format!("{}", err))) as Box<Error>),
+		None => backend
+			.storage(key)
+			.map_err(|err| Box::new(ExecutionError::Backend(format!("{}", err))) as Box<dyn Error>),
 	}
 }
 
diff --git a/substrate/core/state-machine/src/proving_backend.rs b/substrate/core/state-machine/src/proving_backend.rs
index f9472ed747..60178ff899 100644
--- a/substrate/core/state-machine/src/proving_backend.rs
+++ b/substrate/core/state-machine/src/proving_backend.rs
@@ -193,17 +193,17 @@ impl<'a, S, H> Backend<H> for ProvingBackend<'a, S, H>
 pub fn create_proof_check_backend<H>(
 	root: H::Out,
 	proof: Vec<Vec<u8>>
-) -> Result<TrieBackend<MemoryDB<H>, H>, Box<Error>>
+) -> Result<TrieBackend<MemoryDB<H>, H>, Box<dyn Error>>
 where
 	H: Hasher,
 {
 	let db = create_proof_check_backend_storage(proof);
 
-	if !db.contains(&root, &[]) {
-		return Err(Box::new(ExecutionError::InvalidProof) as Box<Error>);
+	if db.contains(&root, &[]) {
+		Ok(TrieBackend::new(db, root))
+	} else {
+		Err(Box::new(ExecutionError::InvalidProof))
 	}
-
-	Ok(TrieBackend::new(db, root))
 }
 
 /// Create in-memory storage of proof check backend.
diff --git a/substrate/core/state-machine/src/testing.rs b/substrate/core/state-machine/src/testing.rs
index 3934e726af..68b9d28752 100644
--- a/substrate/core/state-machine/src/testing.rs
+++ b/substrate/core/state-machine/src/testing.rs
@@ -37,7 +37,7 @@ pub struct TestExternalities<H: Hasher, N: ChangesTrieBlockNumber> {
 	overlay: OverlayedChanges,
 	backend: InMemory<H>,
 	changes_trie_storage: ChangesTrieInMemoryStorage<H, N>,
-	offchain: Option<Box<offchain::Externalities>>,
+	offchain: Option<Box<dyn offchain::Externalities>>,
 }
 
 impl<H: Hasher, N: ChangesTrieBlockNumber> TestExternalities<H, N> {
@@ -234,7 +234,7 @@ impl<H, N> Externalities<H> for TestExternalities<H, N>
 		)?.map(|(root, _)| root.clone()))
 	}
 
-	fn offchain(&mut self) -> Option<&mut offchain::Externalities> {
+	fn offchain(&mut self) -> Option<&mut dyn offchain::Externalities> {
 		self.offchain
 			.as_mut()
 			.map(|x| &mut **x as _)
diff --git a/substrate/core/state-machine/src/trie_backend_essence.rs b/substrate/core/state-machine/src/trie_backend_essence.rs
index 89a5b42a84..fc30f94f05 100644
--- a/substrate/core/state-machine/src/trie_backend_essence.rs
+++ b/substrate/core/state-machine/src/trie_backend_essence.rs
@@ -153,8 +153,8 @@ impl<'a,
 > hash_db::AsPlainDB<H::Out, DBValue>
 	for Ephemeral<'a, S, H>
 {
-	fn as_plain_db<'b>(&'b self) -> &'b (hash_db::PlainDB<H::Out, DBValue> + 'b) { self }
-	fn as_plain_db_mut<'b>(&'b mut self) -> &'b mut (hash_db::PlainDB<H::Out, DBValue> + 'b) { self }
+	fn as_plain_db<'b>(&'b self) -> &'b (dyn hash_db::PlainDB<H::Out, DBValue> + 'b) { self }
+	fn as_plain_db_mut<'b>(&'b mut self) -> &'b mut (dyn hash_db::PlainDB<H::Out, DBValue> + 'b) { self }
 }
 
 impl<'a,
@@ -163,8 +163,8 @@ impl<'a,
 > hash_db::AsHashDB<H, DBValue>
 	for Ephemeral<'a, S, H>
 {
-	fn as_hash_db<'b>(&'b self) -> &'b (hash_db::HashDB<H, DBValue> + 'b) { self }
-	fn as_hash_db_mut<'b>(&'b mut self) -> &'b mut (hash_db::HashDB<H, DBValue> + 'b) { self }
+	fn as_hash_db<'b>(&'b self) -> &'b (dyn hash_db::HashDB<H, DBValue> + 'b) { self }
+	fn as_hash_db_mut<'b>(&'b mut self) -> &'b mut (dyn hash_db::HashDB<H, DBValue> + 'b) { self }
 }
 
 impl<'a, S: TrieBackendStorage<H>, H: Hasher> Ephemeral<'a, S, H> {
@@ -275,7 +275,7 @@ pub trait TrieBackendStorage<H: Hasher>: Send + Sync {
 }
 
 // This implementation is used by normal storage trie clients.
-impl<H: Hasher> TrieBackendStorage<H> for Arc<Storage<H>> {
+impl<H: Hasher> TrieBackendStorage<H> for Arc<dyn Storage<H>> {
 	type Overlay = PrefixedMemoryDB<H>;
 
 	fn get(&self, key: &H::Out, prefix: &[u8]) -> Result<Option<DBValue>, String> {
diff --git a/substrate/core/telemetry/src/lib.rs b/substrate/core/telemetry/src/lib.rs
index 16bc69ec00..3f980c5929 100644
--- a/substrate/core/telemetry/src/lib.rs
+++ b/substrate/core/telemetry/src/lib.rs
@@ -38,14 +38,14 @@ pub struct TelemetryConfig {
 	pub endpoints: TelemetryEndpoints,
 	/// What do do when we connect to the servers.
 	/// Note that this closure is executed each time we connect to a telemetry endpoint.
-	pub on_connect: Box<Fn() + Send + Sync + 'static>,
+	pub on_connect: Box<dyn Fn() + Send + Sync + 'static>,
 }
 
 /// Telemetry service guard.
 pub type Telemetry = slog_scope::GlobalLoggerGuard;
 
 /// Size of the channel for passing messages to telemetry thread.
-const CHANNEL_SIZE: usize = 262144;
+const CHANNEL_SIZE: usize = 262_144;
 
 /// Log levels.
 pub const SUBSTRATE_DEBUG: &str = "9";
@@ -154,7 +154,7 @@ pub fn init_telemetry(config: TelemetryConfig) -> slog_scope::GlobalLoggerGuard
 		});
 	});
 
-	return logger_guard;
+	logger_guard
 }
 
 /// Translates to `slog_scope::info`, but contains an additional verbosity
@@ -172,7 +172,7 @@ macro_rules! telemetry {
 struct Connection {
 	out: ws::Sender,
 	out_sync: Arc<Mutex<Option<ws::Sender>>>,
-	on_connect: Arc<Box<Fn() + Send + Sync + 'static>>,
+	on_connect: Arc<Box<dyn Fn() + Send + Sync + 'static>>,
 	url: String,
 }
 
@@ -180,7 +180,7 @@ impl Connection {
 	fn new(
 		out: ws::Sender,
 		out_sync: Arc<Mutex<Option<ws::Sender>>>,
-		on_connect: Arc<Box<Fn() + Send + Sync + 'static>>,
+		on_connect: Arc<Box<dyn Fn() + Send + Sync + 'static>>,
 		url: String
 	) -> Self {
 		Connection {
diff --git a/substrate/core/transaction-pool/graph/src/error.rs b/substrate/core/transaction-pool/graph/src/error.rs
index acf3fa4514..07e0324354 100644
--- a/substrate/core/transaction-pool/graph/src/error.rs
+++ b/substrate/core/transaction-pool/graph/src/error.rs
@@ -35,7 +35,7 @@ pub enum Error {
 	TemporarilyBanned,
 	/// The transaction is already in the pool.
 	#[display(fmt="[{:?}] Already imported", _0)]
-	AlreadyImported(Box<std::any::Any + Send>),
+	AlreadyImported(Box<dyn std::any::Any + Send>),
 	/// The transaction cannot be imported cause it's a replacement and has too low priority.
 	#[display(fmt="Too low priority ({} > {})", old, new)]
 	TooLowPriority {
diff --git a/substrate/core/trie/src/lib.rs b/substrate/core/trie/src/lib.rs
index 1322038d78..6298f10bf4 100644
--- a/substrate/core/trie/src/lib.rs
+++ b/substrate/core/trie/src/lib.rs
@@ -43,9 +43,9 @@ pub type TrieError<H> = trie_db::TrieError<H, Error>;
 pub trait AsHashDB<H: Hasher>: hash_db::AsHashDB<H, trie_db::DBValue> {}
 impl<H: Hasher, T: hash_db::AsHashDB<H, trie_db::DBValue>> AsHashDB<H> for T {}
 /// As in `hash_db`, but less generic, trait exposed.
-pub type HashDB<'a, H> = hash_db::HashDB<H, trie_db::DBValue> + 'a;
+pub type HashDB<'a, H> = dyn hash_db::HashDB<H, trie_db::DBValue> + 'a;
 /// As in `hash_db`, but less generic, trait exposed.
-pub type PlainDB<'a, K> = hash_db::PlainDB<K, trie_db::DBValue> + 'a;
+pub type PlainDB<'a, K> = dyn hash_db::PlainDB<K, trie_db::DBValue> + 'a;
 /// As in `memory_db::MemoryDB` that uses prefixed storage key scheme.
 pub type PrefixedMemoryDB<H> = memory_db::MemoryDB<H, memory_db::PrefixedKey<H>, trie_db::DBValue>;
 /// As in `memory_db::MemoryDB` that uses prefixed storage key scheme.
@@ -471,7 +471,7 @@ mod tests {
 	}
 
 	fn populate_trie<'db>(
-		db: &'db mut HashDB<Blake2Hasher, DBValue>,
+		db: &'db mut dyn HashDB<Blake2Hasher, DBValue>,
 		root: &'db mut <Blake2Hasher as Hasher>::Out,
 		v: &[(Vec<u8>, Vec<u8>)]
 	) -> TrieDBMut<'db, Blake2Hasher> {
diff --git a/substrate/core/trie/src/node_header.rs b/substrate/core/trie/src/node_header.rs
index 4f7617c068..2c01189f8a 100644
--- a/substrate/core/trie/src/node_header.rs
+++ b/substrate/core/trie/src/node_header.rs
@@ -60,12 +60,12 @@ impl Decode for NodeHeader {
 		Some(match input.read_byte()? {
 			EMPTY_TRIE => NodeHeader::Null,							// 0
 
-			i @ LEAF_NODE_OFFSET ... LEAF_NODE_SMALL_MAX =>			// 1 ... (127 - 1)
+			i @ LEAF_NODE_OFFSET ..= LEAF_NODE_SMALL_MAX =>			// 1 ... (127 - 1)
 				NodeHeader::Leaf((i - LEAF_NODE_OFFSET) as usize),
 			LEAF_NODE_BIG =>										// 127
 				NodeHeader::Leaf(input.read_byte()? as usize + LEAF_NODE_THRESHOLD as usize),
 
-			i @ EXTENSION_NODE_OFFSET ... EXTENSION_NODE_SMALL_MAX =>// 128 ... (253 - 1)
+			i @ EXTENSION_NODE_OFFSET ..= EXTENSION_NODE_SMALL_MAX =>// 128 ... (253 - 1)
 				NodeHeader::Extension((i - EXTENSION_NODE_OFFSET) as usize),
 			EXTENSION_NODE_BIG =>									// 253
 				NodeHeader::Extension(input.read_byte()? as usize + EXTENSION_NODE_THRESHOLD as usize),
diff --git a/substrate/core/trie/src/trie_stream.rs b/substrate/core/trie/src/trie_stream.rs
index 123ab1ea16..913cff2c5a 100644
--- a/substrate/core/trie/src/trie_stream.rs
+++ b/substrate/core/trie/src/trie_stream.rs
@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
-//! `TrieStream` implementation for Substrate's trie format. 
+//! `TrieStream` implementation for Substrate's trie format.
 
 use rstd::iter::once;
 use hash_db::Hasher;
@@ -83,7 +83,7 @@ impl trie_root::TrieStream for TrieStream {
 	fn append_substream<H: Hasher>(&mut self, other: Self) {
 		let data = other.out();
 		match data.len() {
-			0...31 => {
+			0..=31 => {
 				data.encode_to(&mut self.buffer)
 			},
 			_ => {
diff --git a/substrate/core/util/fork-tree/src/lib.rs b/substrate/core/util/fork-tree/src/lib.rs
index cba5a1535b..4b6745a354 100644
--- a/substrate/core/util/fork-tree/src/lib.rs
+++ b/substrate/core/util/fork-tree/src/lib.rs
@@ -52,7 +52,7 @@ impl<E: std::error::Error> std::error::Error for Error<E> {
 		}
 	}
 
-	fn cause(&self) -> Option<&std::error::Error> {
+	fn cause(&self) -> Option<&dyn std::error::Error> {
 		None
 	}
 }
diff --git a/substrate/srml/aura/src/lib.rs b/substrate/srml/aura/src/lib.rs
index bc46e98ec2..597618c142 100644
--- a/substrate/srml/aura/src/lib.rs
+++ b/substrate/srml/aura/src/lib.rs
@@ -150,7 +150,6 @@ impl ProvideInherentData for InherentDataProvider {
 	}
 
 	fn error_to_string(&self, error: &[u8]) -> Option<String> {
-		use parity_codec::Decode;
 		RuntimeString::decode(&mut &error[..]).map(Into::into)
 	}
 }
diff --git a/substrate/srml/contract/src/exec.rs b/substrate/srml/contract/src/exec.rs
index 1ab59fa0c2..7a16c9d60d 100644
--- a/substrate/srml/contract/src/exec.rs
+++ b/substrate/srml/contract/src/exec.rs
@@ -703,7 +703,7 @@ mod tests {
 	}
 
 	#[derive(Clone)]
-	struct MockExecutable<'a>(Rc<Fn(MockCtx) -> VmExecResult + 'a>);
+	struct MockExecutable<'a>(Rc<dyn Fn(MockCtx) -> VmExecResult + 'a>);
 
 	impl<'a> MockExecutable<'a> {
 		fn new(f: impl Fn(MockCtx) -> VmExecResult + 'a) -> Self {
diff --git a/substrate/srml/contract/src/tests.rs b/substrate/srml/contract/src/tests.rs
index 29fc1d3a6d..7a19fdb1d6 100644
--- a/substrate/srml/contract/src/tests.rs
+++ b/substrate/srml/contract/src/tests.rs
@@ -300,15 +300,15 @@ fn account_removal_removes_storage() {
 			// Verify that all entries from account 1 is removed, while
 			// entries from account 2 is in place.
 			{
-				assert!(<AccountDb<Test>>::get_storage(&DirectAccountDb, &1, Some(&trie_id1), key1).is_none());
-				assert!(<AccountDb<Test>>::get_storage(&DirectAccountDb, &1, Some(&trie_id1), key2).is_none());
+				assert!(<dyn AccountDb<Test>>::get_storage(&DirectAccountDb, &1, Some(&trie_id1), key1).is_none());
+				assert!(<dyn AccountDb<Test>>::get_storage(&DirectAccountDb, &1, Some(&trie_id1), key2).is_none());
 
 				assert_eq!(
-					<AccountDb<Test>>::get_storage(&DirectAccountDb, &2, Some(&trie_id2), key1),
+					<dyn AccountDb<Test>>::get_storage(&DirectAccountDb, &2, Some(&trie_id2), key1),
 					Some(b"3".to_vec())
 				);
 				assert_eq!(
-					<AccountDb<Test>>::get_storage(&DirectAccountDb, &2, Some(&trie_id2), key2),
+					<dyn AccountDb<Test>>::get_storage(&DirectAccountDb, &2, Some(&trie_id2), key2),
 					Some(b"4".to_vec())
 				);
 			}
diff --git a/substrate/srml/indices/src/address.rs b/substrate/srml/indices/src/address.rs
index 123b8bca89..c76585d216 100644
--- a/substrate/srml/indices/src/address.rs
+++ b/substrate/srml/indices/src/address.rs
@@ -64,7 +64,7 @@ impl<AccountId, AccountIndex> Decode for Address<AccountId, AccountIndex> where
 {
 	fn decode<I: Input>(input: &mut I) -> Option<Self> {
 		Some(match input.read_byte()? {
-			x @ 0x00...0xef => Address::Index(AccountIndex::from(x as u32)),
+			x @ 0x00..=0xef => Address::Index(AccountIndex::from(x as u32)),
 			0xfc => Address::Index(AccountIndex::from(
 				need_more_than(0xef, u16::decode(input)?)? as u32
 			)),
diff --git a/substrate/subkey/src/vanity.rs b/substrate/subkey/src/vanity.rs
index 400b3bae82..2399197e99 100644
--- a/substrate/subkey/src/vanity.rs
+++ b/substrate/subkey/src/vanity.rs
@@ -19,9 +19,9 @@ use super::Crypto;
 
 fn good_waypoint(done: u64) -> u64 {
 	match done {
-		0 ... 1_000_000 => 100_000,
-		0 ... 10_000_000 => 1_000_000,
-		0 ... 100_000_000 => 10_000_000,
+		0 ..= 1_000_000 => 100_000,
+		0 ..= 10_000_000 => 1_000_000,
+		0 ..= 100_000_000 => 10_000_000,
 		_ => 100_000_000,
 	}
 }