diff --git a/substrate/core/client/db/src/lib.rs b/substrate/core/client/db/src/lib.rs
index e839998248..18c8d06e87 100644
--- a/substrate/core/client/db/src/lib.rs
+++ b/substrate/core/client/db/src/lib.rs
@@ -420,7 +420,7 @@ impl<Block: BlockT> Backend<Block> {
 
 		Ok(Backend {
 			storage: Arc::new(storage_db),
-			tries_change_storage: tries_change_storage,
+			tries_change_storage,
 			blockchain,
 			canonicalization_delay,
 		})
diff --git a/substrate/core/sr-primitives/src/generic/block.rs b/substrate/core/sr-primitives/src/generic/block.rs
index 40538a392c..83ef73153a 100644
--- a/substrate/core/sr-primitives/src/generic/block.rs
+++ b/substrate/core/sr-primitives/src/generic/block.rs
@@ -52,7 +52,7 @@ impl<Block: BlockT> Copy for BlockId<Block> {}
 
 #[cfg(feature = "std")]
 impl<Block: BlockT> fmt::Display for BlockId<Block> {
-	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		write!(f, "{:?}", self)
 	}
 }
diff --git a/substrate/core/state-db/src/lib.rs b/substrate/core/state-db/src/lib.rs
index 45a77d369d..d26fdf0ee3 100644
--- a/substrate/core/state-db/src/lib.rs
+++ b/substrate/core/state-db/src/lib.rs
@@ -21,9 +21,9 @@
 //!
 //! # Canonicalization.
 //! Canonicalization window tracks a tree of blocks identified by header hash. The in-memory
-//! overlay allows to get any node that was was inserted in any any of the blocks within the window.
+//! overlay allows to get any node that was inserted in any of the blocks within the window.
 //! The tree is journaled to the backing database and rebuilt on startup.
-//! Canonicalization function select one root from the top of the tree and discards all other roots and
+//! Canonicalization function selects one root from the top of the tree and discards all other roots and
 //! their subtrees.
 //!
 //! # Pruning.
@@ -83,7 +83,7 @@ pub enum Error<E: fmt::Debug> {
 }
 
 impl<E: fmt::Debug> fmt::Debug for Error<E> {
-	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		match self {
 			Error::Db(e) => e.fmt(f),
 			Error::Decoding => write!(f, "Error decoding slicable value"),
@@ -174,7 +174,7 @@ impl<BlockHash: Hash, Key: Hash> StateDbSync<BlockHash, Key> {
 		Ok(StateDbSync {
 			mode,
 			non_canonical,
-			pruning: pruning,
+			pruning,
 			pinned: Default::default(),
 		})
 	}
diff --git a/substrate/core/state-db/src/noncanonical.rs b/substrate/core/state-db/src/noncanonical.rs
index b0afe0b2cc..7efa2b3b6b 100644
--- a/substrate/core/state-db/src/noncanonical.rs
+++ b/substrate/core/state-db/src/noncanonical.rs
@@ -103,7 +103,7 @@ impl<BlockHash: Hash, Key: Hash> NonCanonicalOverlay<BlockHash, Key> {
 			trace!(target: "state-db", "Finished reading uncanonicalized journal, {} entries", total);
 		}
 		Ok(NonCanonicalOverlay {
-			last_canonicalized: last_canonicalized,
+			last_canonicalized,
 			levels,
 			parents,
 			last_canonicalized_overlay: Default::default(),
@@ -212,8 +212,8 @@ impl<BlockHash: Hash, Key: Hash> NonCanonicalOverlay<BlockHash, Key> {
 				commit.data.inserted = self.last_canonicalized_overlay.iter().map(|(k, v)| (k.clone(), v.clone())).collect();
 				commit.data.deleted = overlay.deleted;
 			} else {
-				// TODO: borrow checker won't allow us to split out mutable refernces
-				// required for recursive processing. A more efficient implementaion
+				// TODO: borrow checker won't allow us to split out mutable references
+				// required for recursive processing. A more efficient implementation
 				// that does not require converting to vector is possible
 				let mut vec: Vec<_> = self.levels.drain(..).collect();
 				Self::discard(&mut vec, &mut self.parents, &mut discarded_journals, 0, &overlay.hash);
diff --git a/substrate/srml/balances/src/address.rs b/substrate/srml/balances/src/address.rs
index 01fb254395..e50daaa6bc 100644
--- a/substrate/srml/balances/src/address.rs
+++ b/substrate/srml/balances/src/address.rs
@@ -40,7 +40,7 @@ impl<AccountId, AccountIndex> fmt::Display for Address<AccountId, AccountIndex>
 	AccountId: Member,
 	AccountIndex: Member,
 {
-	fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		write!(f, "{:?}", self)
 	}
 }