diff --git a/Cargo.toml b/Cargo.toml
index 6988c13252..8856789b40 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -31,7 +31,7 @@ pallet-indices = { git = "https://github.com/paritytech/substrate/", package = "
 substrate-rpc-api = { git = "https://github.com/paritytech/substrate/", package = "sc-rpc-api" }
 substrate-rpc-primitives = { git = "https://github.com/paritytech/substrate/", package = "substrate-rpc-primitives" }
 substrate-primitives = { git = "https://github.com/paritytech/substrate/", package = "substrate-primitives" }
-txpool = { git = "https://github.com/paritytech/substrate/", package = "sc-transaction-graph" }
+txpool-api = { git = "https://github.com/paritytech/substrate/", package = "sp-transaction-pool-api" }
 
 [dev-dependencies]
 env_logger = "0.7"
diff --git a/src/events.rs b/src/events.rs
index 419889cedc..984f0a27d5 100644
--- a/src/events.rs
+++ b/src/events.rs
@@ -157,7 +157,7 @@ impl<T: System + Balances + 'static> EventsDecoder<T> {
         let mut missing = HashSet::new();
         let mut ignore_set = HashSet::new();
         ignore_set.extend(ignore);
-        for module in self.metadata.modules() {
+        for module in self.metadata.modules_with_events() {
             for event in module.events() {
                 for arg in event.arguments() {
                     for primitive in arg.primitives() {
@@ -220,15 +220,14 @@ impl<T: System + Balances + 'static> EventsDecoder<T> {
             let phase = Phase::decode(input)?;
             let module_variant = input.read_byte()? as u8;
 
-            let module_name = self.metadata.module_name(module_variant)?;
-            let event = if module_name == "System" {
+            let module = self.metadata.module_with_events(module_variant)?;
+            let event = if module.name() == "System" {
                 let system_event = SystemEvent::decode(input)?;
                 RuntimeEvent::System(system_event)
             } else {
                 let event_variant = input.read_byte()? as u8;
-                let module = self.metadata.module(&module_name)?;
                 let event_metadata = module.event(event_variant)?;
-                log::debug!("decoding event '{}::{}'", module_name, event_metadata.name);
+                log::debug!("decoding event '{}::{}'", module.name(), event_metadata.name);
 
                 let mut event_data = Vec::<u8>::new();
                 self.decode_raw_bytes(
@@ -237,7 +236,7 @@ impl<T: System + Balances + 'static> EventsDecoder<T> {
                     &mut event_data,
                 )?;
                 RuntimeEvent::Raw(RawEvent {
-                    module: module_name.clone(),
+                    module: module.name().to_string(),
                     variant: event_metadata.name.clone(),
                     data: event_data,
                 })
diff --git a/src/lib.rs b/src/lib.rs
index 1417d5a1f2..7a8d58c6c8 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -339,7 +339,7 @@ where
         let genesis_hash = self.genesis_hash;
         let call = self
             .metadata()
-            .module(&call.module)
+            .module_with_calls(&call.module)
             .and_then(|module| module.call(&call.function, call.args))?;
 
         log::info!(
@@ -527,7 +527,7 @@ mod tests {
     fn test_chain_read_metadata() {
         let (_, client) = test_setup();
 
-        let balances = client.metadata().module("Balances").unwrap();
+        let balances = client.metadata().module_with_calls("Balances").unwrap();
         let dest = substrate_keyring::AccountKeyring::Bob.to_account_id();
         let address: Address = dest.clone().into();
         let amount: Balance = 10_000;
@@ -541,7 +541,10 @@ mod tests {
         let free_balance =
             <pallet_balances::FreeBalance<node_runtime::Runtime>>::hashed_key_for(&dest);
         let free_balance_key = StorageKey(free_balance);
-        let free_balance_key2 = balances
+        let free_balance_key2 = client
+            .metadata()
+            .module("Balances")
+            .unwrap()
             .storage("FreeBalance")
             .unwrap()
             .get_map::<AccountId, Balance>()
diff --git a/src/metadata.rs b/src/metadata.rs
index 61e6e2a63a..52a2c981fb 100644
--- a/src/metadata.rs
+++ b/src/metadata.rs
@@ -43,6 +43,8 @@ use crate::codec::Encoded;
 pub enum MetadataError {
     #[error("Module not found")]
     ModuleNotFound(String),
+    #[error("Module with events not found")]
+    ModuleWithEventsNotFound(u8),
     #[error("Call not found")]
     CallNotFound(&'static str),
     #[error("Event not found")]
@@ -58,14 +60,11 @@ pub enum MetadataError {
 #[derive(Clone, Debug)]
 pub struct Metadata {
     modules: HashMap<String, ModuleMetadata>,
-    modules_by_event_index: HashMap<u8, String>,
+    modules_with_calls: HashMap<String, ModuleWithCalls>,
+    modules_with_events: HashMap<String, ModuleWithEvents>,
 }
 
 impl Metadata {
-    pub fn modules(&self) -> impl Iterator<Item = &ModuleMetadata> {
-        self.modules.values()
-    }
-
     pub fn module<S>(&self, name: S) -> Result<&ModuleMetadata, MetadataError>
     where
         S: ToString,
@@ -76,11 +75,28 @@ impl Metadata {
             .ok_or(MetadataError::ModuleNotFound(name))
     }
 
-    pub fn module_name(&self, module_index: u8) -> Result<String, MetadataError> {
-        self.modules_by_event_index
-            .get(&module_index)
-            .cloned()
-            .ok_or(MetadataError::EventNotFound(module_index))
+    pub fn module_with_calls<S>(&self, name: S) -> Result<&ModuleWithCalls, MetadataError>
+    where
+        S: ToString,
+    {
+        let name = name.to_string();
+        self.modules_with_calls
+            .get(&name)
+            .ok_or(MetadataError::ModuleNotFound(name))
+    }
+
+    pub fn modules_with_events(&self) -> impl Iterator<Item = &ModuleWithEvents> {
+        self.modules_with_events.values()
+    }
+
+    pub fn module_with_events(
+        &self,
+        module_index: u8,
+    ) -> Result<&ModuleWithEvents, MetadataError> {
+        self.modules_with_events
+            .values()
+            .find(|&module| module.index == module_index)
+            .ok_or(MetadataError::ModuleWithEventsNotFound(module_index))
     }
 
     pub fn pretty(&self) -> String {
@@ -93,15 +109,19 @@ impl Metadata {
                 string.push_str(storage.as_str());
                 string.push('\n');
             }
-            for call in module.calls.keys() {
-                string.push_str(" c  ");
-                string.push_str(call.as_str());
-                string.push('\n');
+            if let Some(module) = self.modules_with_calls.get(name) {
+                for call in module.calls.keys() {
+                    string.push_str(" c  ");
+                    string.push_str(call.as_str());
+                    string.push('\n');
+                }
             }
-            for event in module.events.values() {
-                string.push_str(" e  ");
-                string.push_str(event.name.as_str());
-                string.push('\n');
+            if let Some(module) = self.modules_with_events.get(name) {
+                for event in module.events.values() {
+                    string.push_str(" e  ");
+                    string.push_str(event.name.as_str());
+                    string.push('\n');
+                }
             }
         }
         string
@@ -110,38 +130,51 @@ impl Metadata {
 
 #[derive(Clone, Debug)]
 pub struct ModuleMetadata {
-    index: u8,
     name: String,
     storage: HashMap<String, StorageMetadata>,
-    calls: HashMap<String, Vec<u8>>,
-    events: HashMap<u8, ModuleEventMetadata>,
     // constants
 }
 
 impl ModuleMetadata {
-    pub fn name(&self) -> &str {
-        &self.name
+    pub fn storage(&self, key: &'static str) -> Result<&StorageMetadata, MetadataError> {
+        self.storage
+            .get(key)
+            .ok_or(MetadataError::StorageNotFound(key))
     }
+}
 
+#[derive(Clone, Debug)]
+pub struct ModuleWithCalls {
+    index: u8,
+    calls: HashMap<String, u8>,
+}
+
+impl ModuleWithCalls {
     pub fn call<T: Encode>(
         &self,
         function: &'static str,
         params: T,
     ) -> Result<Encoded, MetadataError> {
-        let fn_bytes = self
+        let fn_index = self
             .calls
             .get(function)
             .ok_or(MetadataError::CallNotFound(function))?;
-        let mut bytes = vec![self.index];
-        bytes.extend(fn_bytes);
+        let mut bytes = vec![self.index, *fn_index];
         bytes.extend(params.encode());
         Ok(Encoded(bytes))
     }
+}
 
-    pub fn storage(&self, key: &'static str) -> Result<&StorageMetadata, MetadataError> {
-        self.storage
-            .get(key)
-            .ok_or(MetadataError::StorageNotFound(key))
+#[derive(Clone, Debug)]
+pub struct ModuleWithEvents {
+    index: u8,
+    name: String,
+    events: HashMap<u8, ModuleEventMetadata>,
+}
+
+impl ModuleWithEvents {
+    pub fn name(&self) -> &str {
+        &self.name
     }
 
     pub fn events(&self) -> impl Iterator<Item = &ModuleEventMetadata> {
@@ -157,7 +190,8 @@ impl ModuleMetadata {
 
 #[derive(Clone, Debug)]
 pub struct StorageMetadata {
-    prefix: String,
+    module_prefix: String,
+    storage_prefix: String,
     modifier: StorageEntryModifier,
     ty: StorageEntryType,
     default: Vec<u8>,
@@ -169,13 +203,15 @@ impl StorageMetadata {
     ) -> Result<StorageMap<K, V>, MetadataError> {
         match &self.ty {
             StorageEntryType::Map { hasher, .. } => {
-                let prefix = self.prefix.as_bytes().to_vec();
+                let module_prefix = self.module_prefix.as_bytes().to_vec();
+                let storage_prefix = self.storage_prefix.as_bytes().to_vec();
                 let hasher = hasher.to_owned();
                 let default = Decode::decode(&mut &self.default[..])
                     .map_err(|_| MetadataError::MapValueTypeError)?;
                 Ok(StorageMap {
                     _marker: PhantomData,
-                    prefix,
+                    module_prefix,
+                    storage_prefix,
                     hasher,
                     default,
                 })
@@ -188,27 +224,30 @@ impl StorageMetadata {
 #[derive(Clone, Debug)]
 pub struct StorageMap<K, V> {
     _marker: PhantomData<K>,
-    prefix: Vec<u8>,
+    module_prefix: Vec<u8>,
+    storage_prefix: Vec<u8>,
     hasher: StorageHasher,
     default: V,
 }
 
 impl<K: Encode, V: Decode + Clone> StorageMap<K, V> {
     pub fn key(&self, key: K) -> StorageKey {
-        let mut bytes = self.prefix.clone();
-        bytes.extend(key.encode());
+        let mut bytes = substrate_primitives::twox_128(&self.module_prefix).to_vec();
+        bytes.extend(&substrate_primitives::twox_128(&self.storage_prefix)[..]);
+        let encoded_key = key.encode();
         let hash = match self.hasher {
             StorageHasher::Blake2_128 => {
-                substrate_primitives::blake2_128(&bytes).to_vec()
+                substrate_primitives::blake2_128(&encoded_key).to_vec()
             }
             StorageHasher::Blake2_256 => {
-                substrate_primitives::blake2_256(&bytes).to_vec()
+                substrate_primitives::blake2_256(&encoded_key).to_vec()
             }
-            StorageHasher::Twox128 => substrate_primitives::twox_128(&bytes).to_vec(),
-            StorageHasher::Twox256 => substrate_primitives::twox_256(&bytes).to_vec(),
-            StorageHasher::Twox64Concat => substrate_primitives::twox_64(&bytes).to_vec(),
+            StorageHasher::Twox128 => substrate_primitives::twox_128(&encoded_key).to_vec(),
+            StorageHasher::Twox256 => substrate_primitives::twox_256(&encoded_key).to_vec(),
+            StorageHasher::Twox64Concat => substrate_primitives::twox_64(&encoded_key).to_vec(),
         };
-        StorageKey(hash)
+        bytes.extend(hash);
+        StorageKey(bytes)
     }
 
     pub fn default(&self) -> V {
@@ -306,25 +345,66 @@ impl TryFrom<RuntimeMetadataPrefixed> for Metadata {
             return Err(Error::InvalidPrefix)
         }
         let meta = match metadata.1 {
-            RuntimeMetadata::V8(meta) => meta,
+            RuntimeMetadata::V9(meta) => meta,
             _ => return Err(Error::InvalidVersion),
         };
         let mut modules = HashMap::new();
-        let mut modules_by_event_index = HashMap::new();
-        let mut event_index = 0;
-        for (i, module) in convert(meta.modules)?.into_iter().enumerate() {
+        let mut modules_with_calls = HashMap::new();
+        let mut modules_with_events = HashMap::new();
+        for module in convert(meta.modules)?.into_iter() {
             let module_name = convert(module.name.clone())?;
-            let module_metadata = convert_module(i, module)?;
-            // modules with no events have no corresponding definition in the top level enum
-            if !module_metadata.events.is_empty() {
-                modules_by_event_index.insert(event_index, module_name.clone());
-                event_index += 1;
+
+            let mut storage_map = HashMap::new();
+            if let Some(storage) = module.storage {
+                let storage = convert(storage)?;
+                let module_prefix = convert(storage.prefix)?;
+                for entry in convert(storage.entries)?.into_iter() {
+                    let storage_prefix = convert(entry.name.clone())?;
+                    let entry = convert_entry(module_prefix.clone(), storage_prefix.clone(), entry)?;
+                    storage_map.insert(storage_prefix, entry);
+                }
+            }
+            modules.insert(
+                module_name.clone(),
+                ModuleMetadata {
+                    name: module_name.clone(),
+                    storage: storage_map,
+                },
+            );
+
+            if let Some(calls) = module.calls {
+                let mut call_map = HashMap::new();
+                for (index, call) in convert(calls)?.into_iter().enumerate() {
+                    let name = convert(call.name)?;
+                    call_map.insert(name, index as u8);
+                }
+                modules_with_calls.insert(
+                    module_name.clone(),
+                    ModuleWithCalls {
+                        index: modules_with_calls.len() as u8,
+                        calls: call_map,
+                    },
+                );
+            }
+            if let Some(events) = module.event {
+                let mut event_map = HashMap::new();
+                for (index, event) in convert(events)?.into_iter().enumerate() {
+                    event_map.insert(index as u8, convert_event(event)?);
+                }
+                modules_with_events.insert(
+                    module_name.clone(),
+                    ModuleWithEvents {
+                        index: modules_with_events.len() as u8,
+                        name: module_name.clone(),
+                        events: event_map,
+                    },
+                );
             }
-            modules.insert(module_name, module_metadata);
         }
         Ok(Metadata {
             modules,
-            modules_by_event_index,
+            modules_with_calls,
+            modules_with_events,
         })
     }
 }
@@ -336,43 +416,6 @@ fn convert<B: 'static, O: 'static>(dd: DecodeDifferent<B, O>) -> Result<O, Error
     }
 }
 
-fn convert_module(
-    index: usize,
-    module: runtime_metadata::ModuleMetadata,
-) -> Result<ModuleMetadata, Error> {
-    let mut storage_map = HashMap::new();
-    if let Some(storage) = module.storage {
-        let storage = convert(storage)?;
-        let prefix = convert(storage.prefix)?;
-        for entry in convert(storage.entries)?.into_iter() {
-            let entry_name = convert(entry.name.clone())?;
-            let entry_prefix = format!("{} {}", prefix, entry_name);
-            let entry = convert_entry(entry_prefix, entry)?;
-            storage_map.insert(entry_name, entry);
-        }
-    }
-    let mut call_map = HashMap::new();
-    if let Some(calls) = module.calls {
-        for (index, call) in convert(calls)?.into_iter().enumerate() {
-            let name = convert(call.name)?;
-            call_map.insert(name, vec![index as u8]);
-        }
-    }
-    let mut event_map = HashMap::new();
-    if let Some(events) = module.event {
-        for (index, event) in convert(events)?.into_iter().enumerate() {
-            event_map.insert(index as u8, convert_event(event)?);
-        }
-    }
-    Ok(ModuleMetadata {
-        index: index as u8,
-        name: convert(module.name)?,
-        storage: storage_map,
-        calls: call_map,
-        events: event_map,
-    })
-}
-
 fn convert_event(
     event: runtime_metadata::EventMetadata,
 ) -> Result<ModuleEventMetadata, Error> {
@@ -386,12 +429,14 @@ fn convert_event(
 }
 
 fn convert_entry(
-    prefix: String,
+    module_prefix: String,
+    storage_prefix: String,
     entry: runtime_metadata::StorageEntryMetadata,
 ) -> Result<StorageMetadata, Error> {
     let default = convert(entry.default)?;
     Ok(StorageMetadata {
-        prefix,
+        module_prefix,
+        storage_prefix,
         modifier: entry.modifier,
         ty: entry.ty,
         default,
diff --git a/src/rpc.rs b/src/rpc.rs
index fbbfdd456e..89ca279476 100644
--- a/src/rpc.rs
+++ b/src/rpc.rs
@@ -65,7 +65,7 @@ use substrate_rpc_primitives::{
     list::ListOrValue,
     number::NumberOrHex,
 };
-use txpool::watcher::Status;
+use txpool_api::TransactionStatus;
 
 use crate::{
     error::Error,
@@ -194,8 +194,8 @@ impl<T: System + Balances + 'static> Rpc<T> {
         &self,
     ) -> impl Future<Item = MapStream<StorageChangeSet<<T as System>::Hash>>, Error = Error>
     {
-        let events_key = b"System Events";
-        let storage_key = twox_128(events_key);
+        let mut storage_key = twox_128(b"System").to_vec();
+        storage_key.extend(twox_128(b"Events").to_vec());
         log::debug!("Events storage key {:?}", storage_key);
 
         let closure: MapClosure<StorageChangeSet<<T as System>::Hash>> =
@@ -204,7 +204,7 @@ impl<T: System + Balances + 'static> Rpc<T> {
                 event
             });
         self.state
-            .subscribe_storage(Some(vec![StorageKey(storage_key.to_vec())]))
+            .subscribe_storage(Some(vec![StorageKey(storage_key)]))
             .map(|stream: TypedSubscriptionStream<_>| stream.map(closure))
             .map_err(Into::into)
     }
@@ -274,15 +274,15 @@ impl<T: System + Balances + 'static> Rpc<T> {
                             log::info!("received status {:?}", status);
                             match status {
                                 // ignore in progress extrinsic for now
-                                Status::Future | Status::Ready | Status::Broadcast(_) => {
+                                TransactionStatus::Future | TransactionStatus::Ready | TransactionStatus::Broadcast(_) => {
                                     None
                                 }
-                                Status::Finalized(block_hash) => Some(Ok(block_hash)),
-                                Status::Usurped(_) => {
+                                TransactionStatus::Finalized(block_hash) => Some(Ok(block_hash)),
+                                TransactionStatus::Usurped(_) => {
                                     Some(Err("Extrinsic Usurped".into()))
                                 }
-                                Status::Dropped => Some(Err("Extrinsic Dropped".into())),
-                                Status::Invalid => Some(Err("Extrinsic Invalid".into())),
+                                TransactionStatus::Dropped => Some(Err("Extrinsic Dropped".into())),
+                                TransactionStatus::Invalid => Some(Err("Extrinsic Invalid".into())),
                             }
                         })
                         .into_future()