diff --git a/Cargo.lock b/Cargo.lock
index 4b70d4118b84d..18d30e8ce4640 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,3 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "MacTypes-sys"
 version = "1.3.0"
diff --git a/core/client/db/src/lib.rs b/core/client/db/src/lib.rs
index 64b6b63d9bde5..b8452c790ea9f 100644
--- a/core/client/db/src/lib.rs
+++ b/core/client/db/src/lib.rs
@@ -608,7 +608,8 @@ impl<Block: BlockT> Backend<Block> {
 			};
 
 			trace!(target: "db", "Canonicalize block #{} ({:?})", new_canonical, hash);
-			let commit = self.storage.state_db.canonicalize_block(&hash);
+			let commit = self.storage.state_db.canonicalize_block(&hash)
+				.map_err(|e: state_db::Error<io::Error>| client::error::Error::from(format!("State database error: {:?}", e)))?;
 			apply_state_commit(transaction, commit);
 		};
 
@@ -641,7 +642,8 @@ impl<Block: BlockT> Backend<Block> {
 			let lookup_key = ::utils::number_and_hash_to_lookup_key(f_num, f_hash.clone());
 			transaction.put(columns::META, meta_keys::FINALIZED_BLOCK, &lookup_key);
 
-			let commit = self.storage.state_db.canonicalize_block(&f_hash);
+			let commit = self.storage.state_db.canonicalize_block(&f_hash)
+				.map_err(|e: state_db::Error<io::Error>| client::error::Error::from(format!("State database error: {:?}", e)))?;
 			apply_state_commit(transaction, commit);
 
 			// read config from genesis, since it is readonly atm
@@ -654,67 +656,11 @@ impl<Block: BlockT> Backend<Block> {
 
 		Ok(())
 	}
-}
-
-fn apply_state_commit(transaction: &mut DBTransaction, commit: state_db::CommitSet<H256>) {
-	for (key, val) in commit.data.inserted.into_iter() {
-		transaction.put(columns::STATE, &key[..], &val);
-	}
-	for key in commit.data.deleted.into_iter() {
-		transaction.delete(columns::STATE, &key[..]);
-	}
-	for (key, val) in commit.meta.inserted.into_iter() {
-		transaction.put(columns::STATE_META, &key[..], &val);
-	}
-	for key in commit.meta.deleted.into_iter() {
-		transaction.delete(columns::STATE_META, &key[..]);
-	}
-}
-
-impl<Block> client::backend::AuxStore for Backend<Block> where Block: BlockT<Hash=H256> {
-	fn insert_aux<
-		'a,
-		'b: 'a,
-		'c: 'a,
-		I: IntoIterator<Item=&'a(&'c [u8], &'c [u8])>,
-		D: IntoIterator<Item=&'a &'b [u8]>,
-	>(&self, insert: I, delete: D) -> client::error::Result<()> {
-		let mut transaction = DBTransaction::new();
-		for (k, v) in insert {
-			transaction.put(columns::AUX, k, v);
-		}
-		for k in delete {
-			transaction.delete(columns::AUX, k);
-		}
-		self.storage.db.write(transaction).map_err(db_err)?;
-		Ok(())
-	}
-
-	fn get_aux(&self, key: &[u8]) -> Result<Option<Vec<u8>>, client::error::Error> {
-		Ok(self.storage.db.get(columns::AUX, key).map(|r| r.map(|v| v.to_vec())).map_err(db_err)?)
-	}
-}
-
-impl<Block> client::backend::Backend<Block, Blake2Hasher> for Backend<Block> where Block: BlockT<Hash=H256> {
-	type BlockImportOperation = BlockImportOperation<Block, Blake2Hasher>;
-	type Blockchain = BlockchainDb<Block>;
-	type State = CachingState<Blake2Hasher, DbState, Block>;
-	type ChangesTrieStorage = DbChangesTrieStorage<Block>;
 
-	fn begin_operation(&self, block: BlockId<Block>) -> Result<Self::BlockImportOperation, client::error::Error> {
-		let state = self.state_at(block)?;
-		Ok(BlockImportOperation {
-			pending_block: None,
-			old_state: state,
-			db_updates: MemoryDB::default(),
-			storage_updates: Default::default(),
-			changes_trie_updates: MemoryDB::default(),
-			aux_ops: Vec::new(),
-		})
-	}
-
-	fn commit_operation(&self, mut operation: Self::BlockImportOperation)
+	fn try_commit_operation(&self, mut operation: BlockImportOperation<Block, Blake2Hasher>)
 		-> Result<(), client::error::Error>
+		where
+			Block: BlockT<Hash=H256>,
 	{
 		let mut transaction = DBTransaction::new();
 		operation.apply_aux(&mut transaction);
@@ -747,7 +693,7 @@ impl<Block> client::backend::Backend<Block, Blake2Hasher> for Backend<Block> whe
 						retracted.push(r.hash.clone());
 						if r.hash == meta.finalized_hash {
 							warn!("Potential safety failure: reverting finalized block {:?}",
-								(&r.number, &r.hash));
+								  (&r.number, &r.hash));
 
 							return Err(::client::error::ErrorKind::NotInFinalizedChain.into());
 						}
@@ -812,22 +758,27 @@ impl<Block> client::backend::Backend<Block, Blake2Hasher> for Backend<Block> whe
 			let commit = self.storage.state_db.insert_block(&hash, number_u64, &pending_block.header.parent_hash(), changeset)
 				.map_err(|e: state_db::Error<io::Error>| client::error::Error::from(format!("State database error: {:?}", e)))?;
 			apply_state_commit(&mut transaction, commit);
-			self.changes_tries_storage.commit(&mut transaction, operation.changes_trie_updates);
 
 			let finalized = match pending_block.leaf_state {
 				NewBlockState::Final => true,
 				_ => false,
 			};
 
+			let header = &pending_block.header;
+			let is_best = pending_block.leaf_state.is_best();
+			let changes_trie_updates = operation.changes_trie_updates;
+
+
+			self.changes_tries_storage.commit(&mut transaction, changes_trie_updates);
+
 			if finalized {
 				// TODO: ensure best chain contains this block.
 				self.note_finalized(&mut transaction, &pending_block.header, hash)?;
 			} else {
 				// canonicalize blocks which are old enough, regardless of finality.
-				self.force_delayed_canonicalize(&mut transaction, hash, *pending_block.header.number())?
+				self.force_delayed_canonicalize(&mut transaction, hash, *header.number())?
 			}
 
-			let is_best = pending_block.leaf_state.is_best();
 			debug!(target: "db", "DB Commit {:?} ({}), best = {}", hash, number, is_best);
 
 			{
@@ -849,7 +800,7 @@ impl<Block> client::backend::Backend<Block, Blake2Hasher> for Backend<Block> whe
 			self.blockchain.update_meta(
 				hash.clone(),
 				number.clone(),
-				pending_block.leaf_state.is_best(),
+				is_best,
 				finalized,
 			);
 
@@ -865,31 +816,114 @@ impl<Block> client::backend::Backend<Block, Blake2Hasher> for Backend<Block> whe
 		}
 		Ok(())
 	}
+}
+
+fn apply_state_commit(transaction: &mut DBTransaction, commit: state_db::CommitSet<H256>) {
+	for (key, val) in commit.data.inserted.into_iter() {
+		transaction.put(columns::STATE, &key[..], &val);
+	}
+	for key in commit.data.deleted.into_iter() {
+		transaction.delete(columns::STATE, &key[..]);
+	}
+	for (key, val) in commit.meta.inserted.into_iter() {
+		transaction.put(columns::STATE_META, &key[..], &val);
+	}
+	for key in commit.meta.deleted.into_iter() {
+		transaction.delete(columns::STATE_META, &key[..]);
+	}
+}
+
+impl<Block> client::backend::AuxStore for Backend<Block> where Block: BlockT<Hash=H256> {
+	fn insert_aux<
+		'a,
+		'b: 'a,
+		'c: 'a,
+		I: IntoIterator<Item=&'a(&'c [u8], &'c [u8])>,
+		D: IntoIterator<Item=&'a &'b [u8]>,
+	>(&self, insert: I, delete: D) -> client::error::Result<()> {
+		let mut transaction = DBTransaction::new();
+		for (k, v) in insert {
+			transaction.put(columns::AUX, k, v);
+		}
+		for k in delete {
+			transaction.delete(columns::AUX, k);
+		}
+		self.storage.db.write(transaction).map_err(db_err)?;
+		Ok(())
+	}
+
+	fn get_aux(&self, key: &[u8]) -> Result<Option<Vec<u8>>, client::error::Error> {
+		Ok(self.storage.db.get(columns::AUX, key).map(|r| r.map(|v| v.to_vec())).map_err(db_err)?)
+	}
+}
+
+impl<Block> client::backend::Backend<Block, Blake2Hasher> for Backend<Block> where Block: BlockT<Hash=H256> {
+	type BlockImportOperation = BlockImportOperation<Block, Blake2Hasher>;
+	type Blockchain = BlockchainDb<Block>;
+	type State = CachingState<Blake2Hasher, DbState, Block>;
+	type ChangesTrieStorage = DbChangesTrieStorage<Block>;
+
+	fn begin_operation(&self, block: BlockId<Block>) -> Result<Self::BlockImportOperation, client::error::Error> {
+		let state = self.state_at(block)?;
+		Ok(BlockImportOperation {
+			pending_block: None,
+			old_state: state,
+			db_updates: MemoryDB::default(),
+			storage_updates: Default::default(),
+			changes_trie_updates: MemoryDB::default(),
+			aux_ops: Vec::new(),
+		})
+	}
+
+	fn commit_operation(&self, operation: Self::BlockImportOperation)
+		-> Result<(), client::error::Error>
+	{
+		match self.try_commit_operation(operation) {
+			Ok(_) => {
+				self.storage.state_db.apply_pending();
+				Ok(())
+			},
+			e @ Err(_) => {
+				self.storage.state_db.revert_pending();
+				e
+			}
+		}
+	}
 
 	fn finalize_block(&self, block: BlockId<Block>, justification: Option<Justification>)
 		-> Result<(), client::error::Error>
 	{
 		use runtime_primitives::traits::Header;
 
-		if let Some(header) = ::client::blockchain::HeaderBackend::header(&self.blockchain, block)? {
-			let mut transaction = DBTransaction::new();
-			// TODO: ensure best chain contains this block.
-			let hash = header.hash();
-			self.note_finalized(&mut transaction, &header, hash.clone())?;
-			if let Some(justification) = justification {
-				let number = header.number().clone();
-				transaction.put(
-					columns::JUSTIFICATION,
-					&::utils::number_and_hash_to_lookup_key(number, hash.clone()),
-					&justification.encode(),
-				);
+		let commit = || {
+			if let Some(header) = ::client::blockchain::HeaderBackend::header(&self.blockchain, block)? {
+				let mut transaction = DBTransaction::new();
+				// TODO: ensure best chain contains this block.
+				let hash = header.hash();
+				self.note_finalized(&mut transaction, &header, hash.clone())?;
+				if let Some(justification) = justification {
+					let number = header.number().clone();
+					transaction.put(
+						columns::JUSTIFICATION,
+						&::utils::number_and_hash_to_lookup_key(number, hash.clone()),
+						&justification.encode(),
+					);
+				}
+				self.storage.db.write(transaction).map_err(db_err)?;
+				self.blockchain.update_meta(hash, header.number().clone(), false, true);
+				Ok(())
+			} else {
+				Err(client::error::ErrorKind::UnknownBlock(format!("Cannot finalize block {:?}", block)).into())
+			}
+		};
+		match commit() {
+			Ok(()) => self.storage.state_db.apply_pending(),
+			e @ Err(_) => {
+				self.storage.state_db.revert_pending();
+				return e;
 			}
-			self.storage.db.write(transaction).map_err(db_err)?;
-			self.blockchain.update_meta(hash, header.number().clone(), false, true);
-			Ok(())
-		} else {
-			Err(client::error::ErrorKind::UnknownBlock(format!("Cannot finalize block {:?}", block)).into())
 		}
+		Ok(())
 	}
 
 	fn changes_trie_storage(&self) -> Option<&Self::ChangesTrieStorage> {
diff --git a/core/executor/wasm/Cargo.lock b/core/executor/wasm/Cargo.lock
index 933a8fc20ec09..6047767b11ac8 100644
--- a/core/executor/wasm/Cargo.lock
+++ b/core/executor/wasm/Cargo.lock
@@ -1,3 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "arrayvec"
 version = "0.4.7"
@@ -11,11 +13,6 @@ name = "byteorder"
 version = "1.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "crunchy"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "crunchy"
 version = "0.2.1"
@@ -32,14 +29,14 @@ dependencies = [
 [[package]]
 name = "hash-db"
 version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#e61df32342920f602a9d8d71caa5117c779d3ff1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "hash256-std-hasher"
-version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#e61df32342920f602a9d8d71caa5117c779d3ff1"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "crunchy 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crunchy 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -144,7 +141,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "sr-io"
 version = "0.1.0"
 dependencies = [
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 0.1.0",
@@ -178,8 +175,8 @@ name = "substrate-primitives"
 version = "0.1.0"
 dependencies = [
  "byteorder 1.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "hash256-std-hasher 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hash256-std-hasher 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec-derive 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "primitive-types 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -216,11 +213,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [metadata]
 "checksum arrayvec 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)" = "a1e964f9e24d588183fcb43503abda40d288c8657dfc27311516ce2f05675aef"
 "checksum byteorder 1.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "90492c5858dd7d2e78691cfb89f90d273a2800fc11d98f60786e5d87e2f83781"
-"checksum crunchy 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "a2f4a431c5c9f662e1200b7c7f02c34e91361150e382089a8f2dec3ba680cbda"
 "checksum crunchy 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c240f247c278fa08a6d4820a6a222bfc6e0d999e51ba67be94f44c905b2161f2"
 "checksum fixed-hash 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a557e80084b05c32b455963ff565a9de6f2866da023d6671705c6aff6f65e01c"
-"checksum hash-db 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
-"checksum hash256-std-hasher 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
+"checksum hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "dc5ec43724866bbc8337e09cab4d4b5f9fdbbe589f04bdc8bfda906a639ad338"
+"checksum hash256-std-hasher 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "5fc2d94c8e127b205b3caf6fd3013fb5e5b314234bb0b9bea6588c52fddbb82b"
 "checksum impl-codec 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9c88568d828291c50eed30cd7fb9f8e688ad0013620186fa3e777b9f206c79f2"
 "checksum nodrop 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)" = "9a2228dca57108069a5262f2ed8bd2e82496d2e074a06d1ccc7ce1687b6ae0a2"
 "checksum parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e7b6a1290fe78aa6bbb5f3338ecede3062687a98b9e40cd1dbcaa47261d44097"
diff --git a/core/executor/wasm/build.sh b/core/executor/wasm/build.sh
index ecd7b67540873..256089ab076ec 100755
--- a/core/executor/wasm/build.sh
+++ b/core/executor/wasm/build.sh
@@ -6,7 +6,7 @@ if cargo --version | grep -q "nightly"; then
 else
 	CARGO_CMD="cargo +nightly"
 fi
-$CARGO_CMD build --target=wasm32-unknown-unknown --release
+RUSTFLAGS="-C link-arg=--export-table" $CARGO_CMD build --target=wasm32-unknown-unknown --release
 for i in test
 do
 	wasm-gc target/wasm32-unknown-unknown/release/runtime_$i.wasm target/wasm32-unknown-unknown/release/runtime_$i.compact.wasm
diff --git a/core/state-db/src/lib.rs b/core/state-db/src/lib.rs
index 51fffa1f2dce4..3a92f4eafaa5d 100644
--- a/core/state-db/src/lib.rs
+++ b/core/state-db/src/lib.rs
@@ -78,8 +78,12 @@ pub enum Error<E: fmt::Debug> {
 	Db(E),
 	/// `Codec` decoding error.
 	Decoding,
-	/// NonCanonical error.
-	NonCanonical,
+	/// Trying to canonicalize invalid block.
+	InvalidBlock,
+	/// Trying to insert block with invalid number.
+	InvalidBlockNumber,
+	/// Trying to insert block with unknown parent.
+	InvalidParent,
 }
 
 impl<E: fmt::Debug> fmt::Debug for Error<E> {
@@ -87,7 +91,9 @@ impl<E: fmt::Debug> fmt::Debug for Error<E> {
 		match self {
 			Error::Db(e) => e.fmt(f),
 			Error::Decoding => write!(f, "Error decoding slicable value"),
-			Error::NonCanonical => write!(f, "Error processing non-canonical data"),
+			Error::InvalidBlock => write!(f, "Trying to canonicalize invalid block"),
+			Error::InvalidBlockNumber => write!(f, "Trying to insert block with invalid number"),
+			Error::InvalidParent => write!(f, "Trying to insert block with unknown parent"),
 		}
 	}
 }
@@ -211,27 +217,25 @@ impl<BlockHash: Hash, Key: Hash> StateDbSync<BlockHash, Key> {
 		}
 	}
 
-	pub fn canonicalize_block(&mut self, hash: &BlockHash) -> CommitSet<Key> {
-		// clear the temporary overlay from the previous canonicalization.
-		self.non_canonical.clear_overlay();
+	pub fn canonicalize_block<E: fmt::Debug>(&mut self, hash: &BlockHash) -> Result<CommitSet<Key>, Error<E>> {
 		let mut commit = match self.mode {
 			PruningMode::ArchiveAll => {
 				CommitSet::default()
 			},
 			PruningMode::ArchiveCanonical => {
-				let mut commit = self.non_canonical.canonicalize(hash);
+				let mut commit = self.non_canonical.canonicalize(hash)?;
 				commit.data.deleted.clear();
 				commit
 			},
 			PruningMode::Constrained(_) => {
-				self.non_canonical.canonicalize(hash)
+				self.non_canonical.canonicalize(hash)?
 			},
 		};
 		if let Some(ref mut pruning) = self.pruning {
 			pruning.note_canonical(hash, &mut commit);
 		}
 		self.prune(&mut commit);
-		commit
+		Ok(commit)
 	}
 
 	pub fn best_canonical(&self) -> u64 {
@@ -290,6 +294,20 @@ impl<BlockHash: Hash, Key: Hash> StateDbSync<BlockHash, Key> {
 		}
 		db.get(key).map_err(|e| Error::Db(e))
 	}
+
+	pub fn apply_pending(&mut self) {
+		self.non_canonical.apply_pending();
+		if let Some(pruning) = &mut self.pruning {
+			pruning.apply_pending();
+		}
+	}
+
+	pub fn revert_pending(&mut self) {
+		if let Some(pruning) = &mut self.pruning {
+			pruning.revert_pending();
+		}
+		self.non_canonical.revert_pending();
+	}
 }
 
 /// State DB maintenance. See module description.
@@ -312,7 +330,7 @@ impl<BlockHash: Hash, Key: Hash> StateDb<BlockHash, Key> {
 	}
 
 	/// Finalize a previously inserted block.
-	pub fn canonicalize_block(&self, hash: &BlockHash) -> CommitSet<Key> {
+	pub fn canonicalize_block<E: fmt::Debug>(&self, hash: &BlockHash) -> Result<CommitSet<Key>, Error<E>> {
 		self.db.write().canonicalize_block(hash)
 	}
 
@@ -347,6 +365,16 @@ impl<BlockHash: Hash, Key: Hash> StateDb<BlockHash, Key> {
 	pub fn is_pruned(&self, number: u64) -> bool {
 		return self.db.read().is_pruned(number)
 	}
+
+	/// Apply all pending changes
+	pub fn apply_pending(&self) {
+		self.db.write().apply_pending();
+	}
+
+	/// Revert all pending changes
+	pub fn revert_pending(&self) {
+		self.db.write().revert_pending();
+	}
 }
 
 #[cfg(test)]
@@ -400,7 +428,9 @@ mod tests {
 				)
 				.unwrap(),
 		);
-		db.commit(&state_db.canonicalize_block(&H256::from_low_u64_be(1)));
+		state_db.apply_pending();
+		db.commit(&state_db.canonicalize_block::<io::Error>(&H256::from_low_u64_be(1)).unwrap());
+		state_db.apply_pending();
 		db.commit(
 			&state_db
 				.insert_block::<io::Error>(
@@ -411,8 +441,11 @@ mod tests {
 				)
 				.unwrap(),
 		);
-		db.commit(&state_db.canonicalize_block(&H256::from_low_u64_be(21)));
-		db.commit(&state_db.canonicalize_block(&H256::from_low_u64_be(3)));
+		state_db.apply_pending();
+		db.commit(&state_db.canonicalize_block::<io::Error>(&H256::from_low_u64_be(21)).unwrap());
+		state_db.apply_pending();
+		db.commit(&state_db.canonicalize_block::<io::Error>(&H256::from_low_u64_be(3)).unwrap());
+		state_db.apply_pending();
 
 		(db, state_db)
 	}
diff --git a/core/state-db/src/noncanonical.rs b/core/state-db/src/noncanonical.rs
index b1d34c09ad3ab..e1859604f027e 100644
--- a/core/state-db/src/noncanonical.rs
+++ b/core/state-db/src/noncanonical.rs
@@ -17,8 +17,8 @@
 //! Canonicalization window.
 //! Maintains trees of block overlays and allows discarding trees/roots
 //! The overlays are added in `insert` and removed in `canonicalize`.
-//! Last canonicalized overlay is kept in memory until next call to `canonicalize` or
-//! `clear_overlay`
+//! All pending changes are kept in memory until next call to `apply_pending` or
+//! `revert_pending`
 
 use std::fmt;
 use std::collections::{HashMap, VecDeque};
@@ -33,7 +33,8 @@ pub struct NonCanonicalOverlay<BlockHash: Hash, Key: Hash> {
 	last_canonicalized: Option<(BlockHash, u64)>,
 	levels: VecDeque<Vec<BlockOverlay<BlockHash, Key>>>,
 	parents: HashMap<BlockHash, BlockHash>,
-	last_canonicalized_overlay: HashMap<Key, DBValue>,
+	pending_canonicalizations: Vec<BlockHash>,
+	pending_insertions: Vec<BlockHash>,
 }
 
 #[derive(Encode, Decode)]
@@ -107,39 +108,45 @@ impl<BlockHash: Hash, Key: Hash> NonCanonicalOverlay<BlockHash, Key> {
 			last_canonicalized,
 			levels,
 			parents,
-			last_canonicalized_overlay: Default::default(),
+			pending_canonicalizations: Default::default(),
+			pending_insertions: Default::default(),
 		})
 	}
 
 	/// Insert a new block into the overlay. If inserted on the second level or lover expects parent to be present in the window.
 	pub fn insert<E: fmt::Debug>(&mut self, hash: &BlockHash, number: u64, parent_hash: &BlockHash, changeset: ChangeSet<Key>) -> Result<CommitSet<Key>, Error<E>> {
 		let mut commit = CommitSet::default();
+		let front_block_number = self.pending_front_block_number();
 		if self.levels.is_empty() && self.last_canonicalized.is_none() {
 			if number < 1 {
-				return Err(Error::NonCanonical);
+				return Err(Error::InvalidBlockNumber);
 			}
 			// assume that parent was canonicalized
 			let last_canonicalized = (parent_hash.clone(), number - 1);
 			commit.meta.inserted.push((to_meta_key(LAST_CANONICAL, &()), last_canonicalized.encode()));
 			self.last_canonicalized = Some(last_canonicalized);
 		} else if self.last_canonicalized.is_some() {
-			if number < self.front_block_number() || number >= self.front_block_number() + self.levels.len() as u64 + 1 {
-				return Err(Error::NonCanonical);
+			if number < front_block_number || number >= front_block_number + self.levels.len() as u64 + 1 {
+				trace!(target: "state-db", "Failed to insert block {}, current is {} .. {})",
+					number,
+					front_block_number,
+					front_block_number + self.levels.len() as u64,
+				);
+				return Err(Error::InvalidBlockNumber);
 			}
 			// check for valid parent if inserting on second level or higher
-			if number == self.front_block_number() {
+			if number == front_block_number {
 				if !self.last_canonicalized.as_ref().map_or(false, |&(ref h, n)| h == parent_hash && n == number - 1) {
-					return Err(Error::NonCanonical);
+					return Err(Error::InvalidParent);
 				}
 			} else if !self.parents.contains_key(&parent_hash) {
-				return Err(Error::NonCanonical);
+				return Err(Error::InvalidParent);
 			}
 		}
-		let level = if self.levels.is_empty() || number == self.front_block_number() + self.levels.len() as u64 {
+		let level = if self.levels.is_empty() || number == front_block_number + self.levels.len() as u64 {
 			self.levels.push_back(Vec::new());
 			self.levels.back_mut().expect("can't be empty after insertion; qed")
 		} else {
-			let front_block_number = self.front_block_number();
 			self.levels.get_mut((number - front_block_number) as usize)
 				.expect("number is [front_block_number .. front_block_number + levels.len()) is asserted in precondition; qed")
 		};
@@ -164,85 +171,118 @@ impl<BlockHash: Hash, Key: Hash> NonCanonicalOverlay<BlockHash, Key> {
 		trace!(target: "state-db", "Inserted uncanonicalized changeset {}.{} ({} inserted, {} deleted)", number, index, journal_record.inserted.len(), journal_record.deleted.len());
 		let journal_record = journal_record.encode();
 		commit.meta.inserted.push((journal_key, journal_record));
+		self.pending_insertions.push(hash.clone());
 		Ok(commit)
 	}
 
-	fn discard(
-		levels: &mut [Vec<BlockOverlay<BlockHash, Key>>],
+	fn discard_descendants(
+		levels: &mut VecDeque<Vec<BlockOverlay<BlockHash, Key>>>,
+		index: usize,
 		parents: &mut HashMap<BlockHash, BlockHash>,
-		discarded_journals: &mut Vec<Vec<u8>>,
-		number: u64,
 		hash: &BlockHash,
 	) {
-		if let Some((level, sublevels)) = levels.split_first_mut() {
+		let mut discarded = Vec::new();
+		if let Some(level) = levels.get_mut(index) {
 			level.retain(|ref overlay| {
 				let parent = parents.get(&overlay.hash).expect("there is a parent entry for each entry in levels; qed").clone();
 				if parent == *hash {
 					parents.remove(&overlay.hash);
-					discarded_journals.push(overlay.journal_key.clone());
-					Self::discard(sublevels, parents, discarded_journals, number + 1, &overlay.hash);
+					discarded.push(overlay.hash.clone());
 					false
 				} else {
 					true
 				}
 			});
 		}
+		for hash in discarded.into_iter() {
+			Self::discard_descendants(levels, index + 1, parents, &hash);
+		}
+	}
+
+	fn discard_journals(&self, level_index: usize, discarded_journals: &mut Vec<Vec<u8>>, hash: &BlockHash) {
+		if let Some(level) = self.levels.get(level_index) {
+			level.iter().for_each(|overlay| {
+				let parent = self.parents.get(&overlay.hash).expect("there is a parent entry for each entry in levels; qed").clone();
+				if parent == *hash {
+					discarded_journals.push(overlay.journal_key.clone());
+					self.discard_journals(level_index + 1, discarded_journals, &overlay.hash);
+				}
+			});
+		}
 	}
 
 	fn front_block_number(&self) -> u64 {
 		self.last_canonicalized.as_ref().map(|&(_, n)| n + 1).unwrap_or(0)
 	}
 
-	pub fn last_canonicalized_block_number(&self) -> u64 {
-		self.last_canonicalized.as_ref().map(|&(_, n)| n).unwrap_or(0)
+	fn pending_front_block_number(&self) -> u64 {
+		self.last_canonicalized
+			.as_ref()
+			.map(|&(_, n)| n + 1 + self.pending_canonicalizations.len() as u64)
+			.unwrap_or(0)
 	}
 
-	/// This may be called when the last finalization commit was applied to the database.
-	pub fn clear_overlay(&mut self) {
-		self.last_canonicalized_overlay.clear();
+	pub fn last_canonicalized_block_number(&self) -> u64 {
+		self.last_canonicalized.as_ref().map(|&(_, n)| n).unwrap_or(0)
 	}
 
 	/// Select a top-level root and canonicalized it. Discards all sibling subtrees and the root.
 	/// Returns a set of changes that need to be added to the DB.
-	pub fn canonicalize(&mut self, hash: &BlockHash) -> CommitSet<Key> {
+	pub fn canonicalize<E: fmt::Debug>(&mut self, hash: &BlockHash) -> Result<CommitSet<Key>, Error<E>> {
 		trace!(target: "state-db", "Canonicalizing {:?}", hash);
-		let level = self.levels.pop_front().expect("no blocks to canonicalize");
-		let index = level.iter().position(|overlay| overlay.hash == *hash)
-			.expect("attempting to canonicalize unknown block");
+		let level = self.levels.get(self.pending_canonicalizations.len()).ok_or_else(|| Error::InvalidBlock)?;
+		let index = level
+			.iter()
+			.position(|overlay| overlay.hash == *hash)
+			.ok_or_else(|| Error::InvalidBlock)?;
 
 		let mut commit = CommitSet::default();
 		let mut discarded_journals = Vec::new();
 		for (i, overlay) in level.into_iter().enumerate() {
-			self.parents.remove(&overlay.hash);
 			if i == index {
-				self.last_canonicalized_overlay = overlay.values;
 				// that's the one we need to canonicalize
-				commit.data.inserted = self.last_canonicalized_overlay.iter().map(|(k, v)| (k.clone(), v.clone())).collect();
-				commit.data.deleted = overlay.deleted;
+				commit.data.inserted = overlay.values.iter().map(|(k, v)| (k.clone(), v.clone())).collect();
+				commit.data.deleted = overlay.deleted.clone();
 			} else {
-				// 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);
-				self.levels.extend(vec.into_iter());
+				self.discard_journals(self.pending_canonicalizations.len() + 1, &mut discarded_journals, &overlay.hash);
 			}
-			// cleanup journal entry
-			discarded_journals.push(overlay.journal_key);
+			discarded_journals.push(overlay.journal_key.clone());
 		}
 		commit.meta.deleted.append(&mut discarded_journals);
-		let last_canonicalized = (hash.clone(), self.front_block_number());
-		commit.meta.inserted.push((to_meta_key(LAST_CANONICAL, &()), last_canonicalized.encode()));
-		self.last_canonicalized = Some(last_canonicalized);
-		trace!(target: "state-db", "Discarded {} records", commit.meta.deleted.len());
-		commit
+		let canonicalized = (hash.clone(), self.front_block_number() + self.pending_canonicalizations.len() as u64);
+		commit.meta.inserted.push((to_meta_key(LAST_CANONICAL, &()), canonicalized.encode()));
+		trace!(target: "state-db", "Discarding {} records", commit.meta.deleted.len());
+		self.pending_canonicalizations.push(hash.clone());
+		Ok(commit)
+	}
+
+	fn apply_canonicalizations(&mut self) {
+		let last = self.pending_canonicalizations.last().cloned();
+		let count = self.pending_canonicalizations.len() as u64;
+		for hash in self.pending_canonicalizations.drain(..) {
+			trace!(target: "state-db", "Post canonicalizing {:?}", hash);
+			let level = self.levels.pop_front().expect("Hash validity is checked in `canonicalize`");
+			let index = level
+				.iter()
+				.position(|overlay| overlay.hash == hash)
+				.expect("Hash validity is checked in `canonicalize`");
+
+			// discard unfinalized overlays
+			for (i, overlay) in level.into_iter().enumerate() {
+				self.parents.remove(&overlay.hash);
+				if i != index {
+					Self::discard_descendants(&mut self.levels, 0, &mut self.parents, &overlay.hash);
+				}
+			}
+		}
+		if let Some(hash) = last {
+			let last_canonicalized = (hash, self.last_canonicalized_block_number() + count);
+			self.last_canonicalized = Some(last_canonicalized);
+		}
 	}
 
 	/// Get a value from the node overlay. This searches in every existing changeset.
 	pub fn get(&self, key: &Key) -> Option<DBValue> {
-		if let Some(value) = self.last_canonicalized_overlay.get(&key) {
-			return Some(value.clone());
-		}
 		for level in self.levels.iter() {
 			for overlay in level.iter() {
 				if let Some(value) = overlay.values.get(&key) {
@@ -264,12 +304,42 @@ impl<BlockHash: Hash, Key: Hash> NonCanonicalOverlay<BlockHash, Key> {
 			commit
 		})
 	}
+
+	fn revert_insertions(&mut self) {
+		self.pending_insertions.reverse();
+		for hash in self.pending_insertions.drain(..) {
+			self.parents.remove(&hash);
+			// find a level. When iterating insertions backwards the hash is always last in the level.
+			let level_index =
+				self.levels.iter().position(|level|
+					level.last().expect("Hash is added in `insert` in reverse order").hash == hash)
+				.expect("Hash is added in insert");
+
+			self.levels[level_index].pop();
+			if self.levels[level_index].is_empty() {
+				debug_assert_eq!(level_index, self.levels.len() - 1);
+				self.levels.pop_back();
+			}
+		}
+	}
+
+	/// Apply all pending changes
+	pub fn apply_pending(&mut self) {
+		self.apply_canonicalizations();
+		self.pending_insertions.clear();
+	}
+
+	/// Revert all pending changes
+	pub fn revert_pending(&mut self) {
+		self.pending_canonicalizations.clear();
+		self.revert_insertions();
+	}
 }
 
 #[cfg(test)]
 mod tests {
 	use std::io;
-	use super::NonCanonicalOverlay;
+	use super::{NonCanonicalOverlay, to_journal_key};
 	use {ChangeSet};
 	use primitives::H256;
 	use test::{make_db, make_changeset};
@@ -292,7 +362,7 @@ mod tests {
 	fn canonicalize_empty_panics() {
 		let db = make_db(&[]);
 		let mut overlay = NonCanonicalOverlay::<H256, H256>::new(&db).unwrap();
-		overlay.canonicalize(&H256::default());
+		overlay.canonicalize::<io::Error>(&H256::default()).unwrap();
 	}
 
 	#[test]
@@ -336,7 +406,7 @@ mod tests {
 		let db = make_db(&[]);
 		let mut overlay = NonCanonicalOverlay::<H256, H256>::new(&db).unwrap();
 		overlay.insert::<io::Error>(&h1, 1, &H256::default(), ChangeSet::default()).unwrap();
-		overlay.canonicalize(&h2);
+		overlay.canonicalize::<io::Error>(&h2).unwrap();
 	}
 
 	#[test]
@@ -351,7 +421,7 @@ mod tests {
 		assert_eq!(insertion.meta.inserted.len(), 2);
 		assert_eq!(insertion.meta.deleted.len(), 0);
 		db.commit(&insertion);
-		let finalization = overlay.canonicalize(&h1);
+		let finalization = overlay.canonicalize::<io::Error>(&h1).unwrap();
 		assert_eq!(finalization.data.inserted.len(), changeset.inserted.len());
 		assert_eq!(finalization.data.deleted.len(), changeset.deleted.len());
 		assert_eq!(finalization.meta.inserted.len(), 1);
@@ -384,7 +454,8 @@ mod tests {
 		let mut overlay = NonCanonicalOverlay::<H256, H256>::new(&db).unwrap();
 		db.commit(&overlay.insert::<io::Error>(&h1, 10, &H256::default(), make_changeset(&[3, 4], &[2])).unwrap());
 		db.commit(&overlay.insert::<io::Error>(&h2, 11, &h1, make_changeset(&[5], &[3])).unwrap());
-		db.commit(&overlay.canonicalize(&h1));
+		db.commit(&overlay.canonicalize::<io::Error>(&h1).unwrap());
+		overlay.apply_pending();
 		assert_eq!(overlay.levels.len(), 1);
 
 		let overlay2 = NonCanonicalOverlay::<H256, H256>::new(&db).unwrap();
@@ -408,15 +479,17 @@ mod tests {
 		assert!(contains(&overlay, 5));
 		assert_eq!(overlay.levels.len(), 2);
 		assert_eq!(overlay.parents.len(), 2);
-		db.commit(&overlay.canonicalize(&h1));
+		db.commit(&overlay.canonicalize::<io::Error>(&h1).unwrap());
+		assert!(contains(&overlay, 5));
+		assert_eq!(overlay.levels.len(), 2);
+		assert_eq!(overlay.parents.len(), 2);
+		overlay.apply_pending();
 		assert_eq!(overlay.levels.len(), 1);
 		assert_eq!(overlay.parents.len(), 1);
-		assert!(contains(&overlay, 5));
-		overlay.clear_overlay();
 		assert!(!contains(&overlay, 5));
 		assert!(contains(&overlay, 7));
-		db.commit(&overlay.canonicalize(&h2));
-		overlay.clear_overlay();
+		db.commit(&overlay.canonicalize::<io::Error>(&h2).unwrap());
+		overlay.apply_pending();
 		assert_eq!(overlay.levels.len(), 0);
 		assert_eq!(overlay.parents.len(), 0);
 		assert!(db.data_eq(&make_db(&[1, 4, 6, 7, 8])));
@@ -425,6 +498,7 @@ mod tests {
 
 	#[test]
 	fn complex_tree() {
+		use crate::MetaDb;
 		let mut db = make_db(&[]);
 
 		// - 1 - 1_1 - 1_1_1
@@ -485,8 +559,8 @@ mod tests {
 		assert_eq!(overlay.last_canonicalized, overlay2.last_canonicalized);
 
 		// canonicalize 1. 2 and all its children should be discarded
-		db.commit(&overlay.canonicalize(&h_1));
-		overlay.clear_overlay();
+		db.commit(&overlay.canonicalize::<io::Error>(&h_1).unwrap());
+		overlay.apply_pending();
 		assert_eq!(overlay.levels.len(), 2);
 		assert_eq!(overlay.parents.len(), 6);
 		assert!(!contains(&overlay, 1));
@@ -495,10 +569,17 @@ mod tests {
 		assert!(!contains(&overlay, 22));
 		assert!(!contains(&overlay, 211));
 		assert!(contains(&overlay, 111));
+		assert!(!contains(&overlay, 211));
+		// check that journals are deleted
+		assert!(db.get_meta(&to_journal_key(1, 0)).unwrap().is_none());
+		assert!(db.get_meta(&to_journal_key(1, 1)).unwrap().is_none());
+		assert!(db.get_meta(&to_journal_key(2, 1)).unwrap().is_some());
+		assert!(db.get_meta(&to_journal_key(2, 2)).unwrap().is_none());
+		assert!(db.get_meta(&to_journal_key(2, 3)).unwrap().is_none());
 
 		// canonicalize 1_2. 1_1 and all its children should be discarded
-		db.commit(&overlay.canonicalize(&h_1_2));
-		overlay.clear_overlay();
+		db.commit(&overlay.canonicalize::<io::Error>(&h_1_2).unwrap());
+		overlay.apply_pending();
 		assert_eq!(overlay.levels.len(), 1);
 		assert_eq!(overlay.parents.len(), 3);
 		assert!(!contains(&overlay, 11));
@@ -508,8 +589,8 @@ mod tests {
 		assert!(contains(&overlay, 123));
 
 		// canonicalize 1_2_2
-		db.commit(&overlay.canonicalize(&h_1_2_2));
-		overlay.clear_overlay();
+		db.commit(&overlay.canonicalize::<io::Error>(&h_1_2_2).unwrap());
+		overlay.apply_pending();
 		assert_eq!(overlay.levels.len(), 0);
 		assert_eq!(overlay.parents.len(), 0);
 		assert!(db.data_eq(&make_db(&[1, 12, 122])));
@@ -538,5 +619,29 @@ mod tests {
 		assert!(overlay.revert_one().is_none());
 	}
 
+	#[test]
+	fn revert_pending_insertion() {
+		let h1 = H256::random();
+		let h2_1 = H256::random();
+		let h2_2 = H256::random();
+		let db = make_db(&[]);
+		let mut overlay = NonCanonicalOverlay::<H256, H256>::new(&db).unwrap();
+		let changeset1 = make_changeset(&[5, 6], &[2]);
+		let changeset2 = make_changeset(&[7, 8], &[5, 3]);
+		let changeset3 = make_changeset(&[9], &[]);
+		overlay.insert::<io::Error>(&h1, 1, &H256::default(), changeset1).unwrap();
+		assert!(contains(&overlay, 5));
+		overlay.insert::<io::Error>(&h2_1, 2, &h1, changeset2).unwrap();
+		overlay.insert::<io::Error>(&h2_2, 2, &h1, changeset3).unwrap();
+		assert!(contains(&overlay, 7));
+		assert!(contains(&overlay, 5));
+		assert!(contains(&overlay, 9));
+		assert_eq!(overlay.levels.len(), 2);
+		assert_eq!(overlay.parents.len(), 3);
+		overlay.revert_pending();
+		assert!(!contains(&overlay, 5));
+		assert_eq!(overlay.levels.len(), 0);
+		assert_eq!(overlay.parents.len(), 0);
+	}
 }
 
diff --git a/core/state-db/src/pruning.rs b/core/state-db/src/pruning.rs
index 91f2b9db91311..028f6a0deed65 100644
--- a/core/state-db/src/pruning.rs
+++ b/core/state-db/src/pruning.rs
@@ -23,6 +23,7 @@
 //! The changes are journaled in the DB.
 
 use std::collections::{HashMap, HashSet, VecDeque};
+use std::mem;
 use codec::{Encode, Decode};
 use {CommitSet, Error, MetaDb, to_meta_key, Hash};
 
@@ -34,6 +35,8 @@ pub struct RefWindow<BlockHash: Hash, Key: Hash> {
 	death_rows: VecDeque<DeathRow<BlockHash, Key>>,
 	death_index: HashMap<Key, u64>,
 	pending_number: u64,
+	pending_records: Vec<(u64, JournalRecord<BlockHash, Key>)>,
+	pending_prunings: usize,
 }
 
 #[derive(Debug, PartialEq, Eq)]
@@ -67,6 +70,8 @@ impl<BlockHash: Hash, Key: Hash> RefWindow<BlockHash, Key> {
 			death_rows: Default::default(),
 			death_index: Default::default(),
 			pending_number: pending_number,
+			pending_records: Default::default(),
+			pending_prunings: 0,
 		};
 		// read the journal
 		trace!(target: "state-db", "Reading pruning journal. Pending #{}", pending_number);
@@ -108,11 +113,11 @@ impl<BlockHash: Hash, Key: Hash> RefWindow<BlockHash, Key> {
 	}
 
 	pub fn window_size(&self) -> u64 {
-		self.death_rows.len() as u64
+		(self.death_rows.len() + self.pending_records.len() - self.pending_prunings) as u64
 	}
 
 	pub fn next_hash(&self) -> Option<BlockHash> {
-		self.death_rows.front().map(|r| r.hash.clone())
+		self.death_rows.get(self.pending_prunings).map(|r| r.hash.clone())
 	}
 
 	pub fn mem_used(&self) -> usize {
@@ -120,20 +125,28 @@ impl<BlockHash: Hash, Key: Hash> RefWindow<BlockHash, Key> {
 	}
 
 	pub fn pending(&self) -> u64 {
-		self.pending_number
+		self.pending_number + self.pending_prunings as u64
 	}
 
 	/// Prune next block. Expects at least one block in the window. Adds changes to `commit`.
 	pub fn prune_one(&mut self, commit: &mut CommitSet<Key>) {
-		let pruned = self.death_rows.pop_front().expect("prune_one is only called with a non-empty window");
-		trace!(target: "state-db", "Pruning {:?} ({} deleted)", pruned.hash, pruned.deleted.len());
-		for k in pruned.deleted.iter() {
-			self.death_index.remove(&k);
+		if let Some(pruned) = self.death_rows.get(self.pending_prunings) {
+			trace!(target: "state-db", "Pruning {:?} ({} deleted)", pruned.hash, pruned.deleted.len());
+			let index = self.pending_number + self.pending_prunings as u64;
+			commit.data.deleted.extend(pruned.deleted.iter().cloned());
+			commit.meta.inserted.push((to_meta_key(LAST_PRUNED, &()), index.encode()));
+			commit.meta.deleted.push(pruned.journal_key.clone());
+			self.pending_prunings += 1;
+		} else if let Some((block, pruned)) = self.pending_records.get(self.pending_prunings - self.death_rows.len()) {
+			trace!(target: "state-db", "Pruning pending{:?} ({} deleted)", pruned.hash, pruned.deleted.len());
+			commit.data.deleted.extend(pruned.deleted.iter().cloned());
+			commit.meta.inserted.push((to_meta_key(LAST_PRUNED, &()), block.encode()));
+			let journal_key = to_journal_key(*block);
+			commit.meta.deleted.push(journal_key);
+			self.pending_prunings += 1;
+		} else {
+			warn!(target: "state-db", "Trying to prune when there's nothing to prune");
 		}
-		commit.data.deleted.extend(pruned.deleted.into_iter());
-		commit.meta.inserted.push((to_meta_key(LAST_PRUNED, &()), self.pending_number.encode()));
-		commit.meta.deleted.push(pruned.journal_key);
-		self.pending_number += 1;
 	}
 
 	/// Add a change set to the window. Creates a journal record and pushes it to `commit`
@@ -146,11 +159,34 @@ impl<BlockHash: Hash, Key: Hash> RefWindow<BlockHash, Key> {
 			inserted,
 			deleted,
 		};
-		let block = self.pending_number + self.window_size();
+		let block = self.pending_number + self.window_size() as u64;
 		let journal_key = to_journal_key(block);
 		commit.meta.inserted.push((journal_key.clone(), journal_record.encode()));
+		self.pending_records.push((block, journal_record));
+	}
+
+	/// Apply all pending changes
+	pub fn apply_pending(&mut self) {
+		for (block, journal_record) in mem::replace(&mut self.pending_records, Default::default()).into_iter() {
+			trace!(target: "state-db", "Applying pruning window record: {}: {:?}", block, journal_record.hash);
+			let journal_key = to_journal_key(block);
+			self.import(&journal_record.hash, journal_key, journal_record.inserted.into_iter(), journal_record.deleted);
+		}
+		for _ in 0 .. self.pending_prunings {
+			let pruned = self.death_rows.pop_front().expect("pending_prunings is always < death_rows.len()");
+			trace!(target: "state-db", "Applying pruning {:?} ({} deleted)", pruned.hash, pruned.deleted.len());
+			for k in pruned.deleted.iter() {
+				self.death_index.remove(&k);
+			}
+			self.pending_number += 1;
+		}
+		self.pending_prunings = 0;
+	}
 
-		self.import(hash, journal_key, journal_record.inserted.into_iter(), journal_record.deleted);
+	/// Revert all pending changes
+	pub fn revert_pending(&mut self) {
+		self.pending_records.clear();
+		self.pending_prunings = 0;
 	}
 }
 
@@ -178,12 +214,16 @@ mod tests {
 	}
 
 	#[test]
-	#[should_panic]
-	fn prune_empty_panics() {
+	fn prune_empty() {
 		let db = make_db(&[]);
 		let mut pruning: RefWindow<H256, H256> = RefWindow::new(&db).unwrap();
 		let mut commit = CommitSet::default();
 		pruning.prune_one(&mut commit);
+		assert_eq!(pruning.pending_number, 0);
+		assert!(pruning.death_rows.is_empty());
+		assert!(pruning.death_index.is_empty());
+		assert!(pruning.pending_prunings == 0);
+		assert!(pruning.pending_records.is_empty());
 	}
 
 	#[test]
@@ -194,6 +234,7 @@ mod tests {
 		let h = H256::random();
 		pruning.note_canonical(&h, &mut commit);
 		db.commit(&commit);
+		pruning.apply_pending();
 		assert!(commit.data.deleted.is_empty());
 		assert_eq!(pruning.death_rows.len(), 1);
 		assert_eq!(pruning.death_index.len(), 2);
@@ -203,6 +244,7 @@ mod tests {
 		let mut commit = CommitSet::default();
 		pruning.prune_one(&mut commit);
 		db.commit(&commit);
+		pruning.apply_pending();
 		assert!(db.data_eq(&make_db(&[2, 4, 5])));
 		assert!(pruning.death_rows.is_empty());
 		assert!(pruning.death_index.is_empty());
@@ -219,6 +261,7 @@ mod tests {
 		let mut commit = make_commit(&[5], &[2]);
 		pruning.note_canonical(&H256::random(), &mut commit);
 		db.commit(&commit);
+		pruning.apply_pending();
 		assert!(db.data_eq(&make_db(&[1, 2, 3, 4, 5])));
 
 		check_journal(&pruning, &db);
@@ -226,10 +269,12 @@ mod tests {
 		let mut commit = CommitSet::default();
 		pruning.prune_one(&mut commit);
 		db.commit(&commit);
+		pruning.apply_pending();
 		assert!(db.data_eq(&make_db(&[2, 3, 4, 5])));
 		let mut commit = CommitSet::default();
 		pruning.prune_one(&mut commit);
 		db.commit(&commit);
+		pruning.apply_pending();
 		assert!(db.data_eq(&make_db(&[3, 4, 5])));
 		assert_eq!(pruning.pending_number, 2);
 	}
@@ -248,6 +293,7 @@ mod tests {
 		pruning.note_canonical(&H256::random(), &mut commit);
 		db.commit(&commit);
 		assert!(db.data_eq(&make_db(&[1, 2, 3])));
+		pruning.apply_pending();
 
 		check_journal(&pruning, &db);
 
@@ -262,6 +308,7 @@ mod tests {
 		pruning.prune_one(&mut commit);
 		db.commit(&commit);
 		assert!(db.data_eq(&make_db(&[1, 3])));
+		pruning.apply_pending();
 		assert_eq!(pruning.pending_number, 3);
 	}
 }
diff --git a/core/state-db/src/test.rs b/core/state-db/src/test.rs
index 487a5c641d1fe..ac78e71a067b8 100644
--- a/core/state-db/src/test.rs
+++ b/core/state-db/src/test.rs
@@ -46,6 +46,7 @@ impl HashDb for TestDb {
 impl TestDb {
 	pub fn commit(&mut self, commit: &CommitSet<H256>) {
 		self.data.extend(commit.data.inserted.iter().cloned());
+		self.meta.extend(commit.meta.inserted.iter().cloned());
 		for k in commit.data.deleted.iter() {
 			self.data.remove(k);
 		}
diff --git a/core/test-runtime/wasm/Cargo.lock b/core/test-runtime/wasm/Cargo.lock
index dd3ee2fea3b12..0a6a69b17ef7f 100644
--- a/core/test-runtime/wasm/Cargo.lock
+++ b/core/test-runtime/wasm/Cargo.lock
@@ -1,3 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "arrayvec"
 version = "0.4.8"
@@ -128,11 +130,6 @@ dependencies = [
  "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "crunchy"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "crunchy"
 version = "0.2.1"
@@ -212,14 +209,14 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "hash-db"
 version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#2616db2a2529098949e5d39aa06dd4e502a9e5f7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "hash256-std-hasher"
-version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#2616db2a2529098949e5d39aa06dd4e502a9e5f7"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "crunchy 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crunchy 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -345,14 +342,6 @@ dependencies = [
  "scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "log"
-version = "0.3.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "log"
 version = "0.4.6"
@@ -391,10 +380,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "memory-db"
-version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#2616db2a2529098949e5d39aa06dd4e502a9e5f7"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -897,7 +886,7 @@ name = "sr-io"
 version = "0.1.0"
 dependencies = [
  "environmental 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 0.1.0",
@@ -933,6 +922,7 @@ dependencies = [
 name = "sr-version"
 version = "0.1.0"
 dependencies = [
+ "impl-serde 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec-derive 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.81 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1017,7 +1007,7 @@ dependencies = [
  "error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "kvdb 0.1.0 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)",
@@ -1104,8 +1094,8 @@ dependencies = [
  "base58 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "blake2-rfc 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "hash256-std-hasher 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hash256-std-hasher 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "impl-serde 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1133,7 +1123,7 @@ dependencies = [
 name = "substrate-state-machine"
 version = "0.1.0"
 dependencies = [
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1141,8 +1131,8 @@ dependencies = [
  "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "substrate-primitives 0.1.0",
  "substrate-trie 0.4.0",
- "trie-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "trie-root 0.9.0 (git+https://github.com/paritytech/trie)",
+ "trie-db 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "trie-root 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1191,11 +1181,11 @@ dependencies = [
 name = "substrate-trie"
 version = "0.4.0"
 dependencies = [
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "memory-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memory-db 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "trie-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "trie-root 0.9.0 (git+https://github.com/paritytech/trie)",
+ "trie-db 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "trie-root 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1398,21 +1388,21 @@ dependencies = [
 
 [[package]]
 name = "trie-db"
-version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#2616db2a2529098949e5d39aa06dd4e502a9e5f7"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "elastic-array 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "trie-root"
-version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#2616db2a2529098949e5d39aa06dd4e502a9e5f7"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1569,7 +1559,6 @@ dependencies = [
 "checksum crossbeam-deque 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4fe1b6f945f824c7a25afe44f62e25d714c0cc523f8e99d8db5cd1026e1269d3"
 "checksum crossbeam-epoch 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2449aaa4ec7ef96e5fb24db16024b935df718e9ae1cec0a1e68feeca2efca7b8"
 "checksum crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e07fc155212827475223f0bcfae57e945e694fc90950ddf3f6695bbfd5555c72"
-"checksum crunchy 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "a2f4a431c5c9f662e1200b7c7f02c34e91361150e382089a8f2dec3ba680cbda"
 "checksum crunchy 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c240f247c278fa08a6d4820a6a222bfc6e0d999e51ba67be94f44c905b2161f2"
 "checksum elastic-array 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "88d4851b005ef16de812ea9acdb7bece2f0a40dd86c07b85631d7dafa54537bb"
 "checksum environmental 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "db746025e3ea695bfa0ae744dbacd5fcfc8db51b9760cf8bd0ab69708bb93c49"
@@ -1581,8 +1570,8 @@ dependencies = [
 "checksum fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2e9763c69ebaae630ba35f74888db465e49e259ba1bc0eda7d06f4a067615d82"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)" = "49e7653e374fe0d0c12de4250f0bdb60680b8c80eed558c5c7538eec9c89e21b"
-"checksum hash-db 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
-"checksum hash256-std-hasher 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
+"checksum hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "dc5ec43724866bbc8337e09cab4d4b5f9fdbbe589f04bdc8bfda906a639ad338"
+"checksum hash256-std-hasher 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "5fc2d94c8e127b205b3caf6fd3013fb5e5b314234bb0b9bea6588c52fddbb82b"
 "checksum heapsize 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1679e6ea370dee694f91f1dc469bf94cf8f52051d147aec3e1f9497c6fc22461"
 "checksum hex-literal 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4da5f0e01bd8a71a224a4eedecaacfcabda388dbb7a80faf04d3514287572d95"
 "checksum hex-literal-impl 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "1d340b6514f232f6db1bd16db65302a5278a04fef9ce867cb932e7e5fa21130a"
@@ -1600,13 +1589,12 @@ dependencies = [
 "checksum lazycell 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
 "checksum libc 0.2.44 (registry+https://github.com/rust-lang/crates.io-index)" = "10923947f84a519a45c8fefb7dd1b3e8c08747993381adee176d7a82b4195311"
 "checksum lock_api 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "62ebf1391f6acad60e5c8b43706dde4582df75c06698ab44511d15016bc2442c"
-"checksum log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "e19e8d5c34a3e0e2223db8e060f9e8264aeeb5c5fc64a4ee9965c062211c024b"
 "checksum log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c84ec4b527950aa83a329754b01dbe3f58361d1c5efacd1f6d68c494d08a17c6"
 "checksum mashup 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "f2d82b34c7fb11bb41719465c060589e291d505ca4735ea30016a91f6fc79c3b"
 "checksum mashup-impl 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "aa607bfb674b4efb310512527d64266b065de3f894fc52f84efcbf7eaa5965fb"
 "checksum matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
 "checksum memoffset 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0f9dc261e2b62d7a622bf416ea3c5245cdd5d9a7fcc428c0d06804dfce1775b3"
-"checksum memory-db 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
+"checksum memory-db 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c0c940ff365f921ac747e7a009d8f9688105acf956f3fbb7fd967920737e935d"
 "checksum memory_units 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "71d96e3f3c0b6325d8ccd83c33b28acb183edcb6c67938ba104ec546854b0882"
 "checksum mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)" = "71646331f2619b1026cc302f87a2b8b648d5c6dd6937846a16cc8ce0f347f432"
 "checksum mio-extras 2.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "46e73a04c2fa6250b8d802134d56d554a9ec2922bf977777c805ea5def61ce40"
@@ -1684,8 +1672,8 @@ dependencies = [
 "checksum tokio-timer 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "4f37f0111d76cc5da132fe9bc0590b9b9cfd079bc7e75ac3846278430a299ff8"
 "checksum tokio-udp 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "66268575b80f4a4a710ef83d087fdfeeabdce9b74c797535fbac18a2cb906e92"
 "checksum tokio-uds 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "99ce87382f6c1a24b513a72c048b2c8efe66cb5161c9061d00bee510f08dc168"
-"checksum trie-db 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
-"checksum trie-root 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
+"checksum trie-db 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9ec6ceb1ad749359cedcf6fa95d7b5104acf70e871e2416e71cabcc3a8b2dbb8"
+"checksum trie-root 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "6294c313431d8bd2dda88db3a57550c4911dd6f7f0e8be6001e23c1e6cbdcf1b"
 "checksum twox-hash 1.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "555cd4909480122bbbf21e34faac4cb08a171f324775670447ed116726c474af"
 "checksum uint 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "082df6964410f6aa929a61ddfafc997e4f32c62c22490e439ac351cec827f436"
 "checksum unicode-bidi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "49f2bd0c6468a8230e1db229cff8029217cf623c767ea5d60bfbd42729ea54d5"
diff --git a/core/test-runtime/wasm/build.sh b/core/test-runtime/wasm/build.sh
index 24a0d162dad2b..45317edcfeb47 100755
--- a/core/test-runtime/wasm/build.sh
+++ b/core/test-runtime/wasm/build.sh
@@ -6,7 +6,7 @@ if cargo --version | grep -q "nightly"; then
 else
 	CARGO_CMD="cargo +nightly"
 fi
-$CARGO_CMD build --target=wasm32-unknown-unknown --release
+RUSTFLAGS="-C link-arg=--export-table" $CARGO_CMD build --target=wasm32-unknown-unknown --release
 for i in substrate_test_runtime
 do
 	wasm-gc target/wasm32-unknown-unknown/release/$i.wasm target/wasm32-unknown-unknown/release/$i.compact.wasm
diff --git a/core/test-runtime/wasm/target/wasm32-unknown-unknown/release/substrate_test_runtime.compact.wasm b/core/test-runtime/wasm/target/wasm32-unknown-unknown/release/substrate_test_runtime.compact.wasm
index 991bf00699648..ca69d9ea8b2aa 100644
Binary files a/core/test-runtime/wasm/target/wasm32-unknown-unknown/release/substrate_test_runtime.compact.wasm and b/core/test-runtime/wasm/target/wasm32-unknown-unknown/release/substrate_test_runtime.compact.wasm differ
diff --git a/node/runtime/wasm/Cargo.lock b/node/runtime/wasm/Cargo.lock
index 0b5a12e7b0d98..3978bedb5b5bb 100644
--- a/node/runtime/wasm/Cargo.lock
+++ b/node/runtime/wasm/Cargo.lock
@@ -1,3 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
 [[package]]
 name = "arrayvec"
 version = "0.4.8"
@@ -128,11 +130,6 @@ dependencies = [
  "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "crunchy"
-version = "0.1.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "crunchy"
 version = "0.2.1"
@@ -212,14 +209,14 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "hash-db"
 version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#2616db2a2529098949e5d39aa06dd4e502a9e5f7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "hash256-std-hasher"
-version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#2616db2a2529098949e5d39aa06dd4e502a9e5f7"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "crunchy 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crunchy 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -345,14 +342,6 @@ dependencies = [
  "scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "log"
-version = "0.3.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "log"
 version = "0.4.6"
@@ -391,10 +380,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "memory-db"
-version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#2616db2a2529098949e5d39aa06dd4e502a9e5f7"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -978,7 +967,7 @@ name = "sr-io"
 version = "0.1.0"
 dependencies = [
  "environmental 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "sr-std 0.1.0",
@@ -1025,6 +1014,7 @@ dependencies = [
 name = "sr-version"
 version = "0.1.0"
 dependencies = [
+ "impl-serde 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec-derive 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.81 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1395,7 +1385,7 @@ dependencies = [
  "error-chain 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)",
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "kvdb 0.1.0 (git+https://github.com/paritytech/parity-common?rev=b0317f649ab2c665b7987b8475878fc4d2e1f81d)",
@@ -1494,8 +1484,8 @@ dependencies = [
  "base58 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "blake2-rfc 0.2.18 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "hash256-std-hasher 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hash256-std-hasher 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "impl-serde 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1523,7 +1513,7 @@ dependencies = [
 name = "substrate-state-machine"
 version = "0.1.0"
 dependencies = [
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1531,8 +1521,8 @@ dependencies = [
  "parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "substrate-primitives 0.1.0",
  "substrate-trie 0.4.0",
- "trie-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "trie-root 0.9.0 (git+https://github.com/paritytech/trie)",
+ "trie-db 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "trie-root 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1553,11 +1543,11 @@ dependencies = [
 name = "substrate-trie"
 version = "0.4.0"
 dependencies = [
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "memory-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memory-db 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "parity-codec 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "trie-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "trie-root 0.9.0 (git+https://github.com/paritytech/trie)",
+ "trie-db 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "trie-root 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1760,21 +1750,21 @@ dependencies = [
 
 [[package]]
 name = "trie-db"
-version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#2616db2a2529098949e5d39aa06dd4e502a9e5f7"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "elastic-array 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
- "log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "trie-root"
-version = "0.9.0"
-source = "git+https://github.com/paritytech/trie#2616db2a2529098949e5d39aa06dd4e502a9e5f7"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "hash-db 0.9.0 (git+https://github.com/paritytech/trie)",
+ "hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1931,7 +1921,6 @@ dependencies = [
 "checksum crossbeam-deque 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4fe1b6f945f824c7a25afe44f62e25d714c0cc523f8e99d8db5cd1026e1269d3"
 "checksum crossbeam-epoch 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2449aaa4ec7ef96e5fb24db16024b935df718e9ae1cec0a1e68feeca2efca7b8"
 "checksum crossbeam-utils 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e07fc155212827475223f0bcfae57e945e694fc90950ddf3f6695bbfd5555c72"
-"checksum crunchy 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)" = "a2f4a431c5c9f662e1200b7c7f02c34e91361150e382089a8f2dec3ba680cbda"
 "checksum crunchy 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c240f247c278fa08a6d4820a6a222bfc6e0d999e51ba67be94f44c905b2161f2"
 "checksum elastic-array 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "88d4851b005ef16de812ea9acdb7bece2f0a40dd86c07b85631d7dafa54537bb"
 "checksum environmental 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "db746025e3ea695bfa0ae744dbacd5fcfc8db51b9760cf8bd0ab69708bb93c49"
@@ -1943,8 +1932,8 @@ dependencies = [
 "checksum fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2e9763c69ebaae630ba35f74888db465e49e259ba1bc0eda7d06f4a067615d82"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum futures 0.1.25 (registry+https://github.com/rust-lang/crates.io-index)" = "49e7653e374fe0d0c12de4250f0bdb60680b8c80eed558c5c7538eec9c89e21b"
-"checksum hash-db 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
-"checksum hash256-std-hasher 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
+"checksum hash-db 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "dc5ec43724866bbc8337e09cab4d4b5f9fdbbe589f04bdc8bfda906a639ad338"
+"checksum hash256-std-hasher 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "5fc2d94c8e127b205b3caf6fd3013fb5e5b314234bb0b9bea6588c52fddbb82b"
 "checksum heapsize 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "1679e6ea370dee694f91f1dc469bf94cf8f52051d147aec3e1f9497c6fc22461"
 "checksum hex-literal 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4da5f0e01bd8a71a224a4eedecaacfcabda388dbb7a80faf04d3514287572d95"
 "checksum hex-literal-impl 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "1d340b6514f232f6db1bd16db65302a5278a04fef9ce867cb932e7e5fa21130a"
@@ -1962,13 +1951,12 @@ dependencies = [
 "checksum lazycell 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
 "checksum libc 0.2.44 (registry+https://github.com/rust-lang/crates.io-index)" = "10923947f84a519a45c8fefb7dd1b3e8c08747993381adee176d7a82b4195311"
 "checksum lock_api 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "62ebf1391f6acad60e5c8b43706dde4582df75c06698ab44511d15016bc2442c"
-"checksum log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "e19e8d5c34a3e0e2223db8e060f9e8264aeeb5c5fc64a4ee9965c062211c024b"
 "checksum log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c84ec4b527950aa83a329754b01dbe3f58361d1c5efacd1f6d68c494d08a17c6"
 "checksum mashup 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "f2d82b34c7fb11bb41719465c060589e291d505ca4735ea30016a91f6fc79c3b"
 "checksum mashup-impl 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "aa607bfb674b4efb310512527d64266b065de3f894fc52f84efcbf7eaa5965fb"
 "checksum matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
 "checksum memoffset 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0f9dc261e2b62d7a622bf416ea3c5245cdd5d9a7fcc428c0d06804dfce1775b3"
-"checksum memory-db 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
+"checksum memory-db 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c0c940ff365f921ac747e7a009d8f9688105acf956f3fbb7fd967920737e935d"
 "checksum memory_units 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "71d96e3f3c0b6325d8ccd83c33b28acb183edcb6c67938ba104ec546854b0882"
 "checksum mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)" = "71646331f2619b1026cc302f87a2b8b648d5c6dd6937846a16cc8ce0f347f432"
 "checksum mio-extras 2.0.5 (registry+https://github.com/rust-lang/crates.io-index)" = "46e73a04c2fa6250b8d802134d56d554a9ec2922bf977777c805ea5def61ce40"
@@ -2049,8 +2037,8 @@ dependencies = [
 "checksum tokio-timer 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "4f37f0111d76cc5da132fe9bc0590b9b9cfd079bc7e75ac3846278430a299ff8"
 "checksum tokio-udp 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "66268575b80f4a4a710ef83d087fdfeeabdce9b74c797535fbac18a2cb906e92"
 "checksum tokio-uds 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "99ce87382f6c1a24b513a72c048b2c8efe66cb5161c9061d00bee510f08dc168"
-"checksum trie-db 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
-"checksum trie-root 0.9.0 (git+https://github.com/paritytech/trie)" = "<none>"
+"checksum trie-db 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9ec6ceb1ad749359cedcf6fa95d7b5104acf70e871e2416e71cabcc3a8b2dbb8"
+"checksum trie-root 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "6294c313431d8bd2dda88db3a57550c4911dd6f7f0e8be6001e23c1e6cbdcf1b"
 "checksum twox-hash 1.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "555cd4909480122bbbf21e34faac4cb08a171f324775670447ed116726c474af"
 "checksum uint 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "082df6964410f6aa929a61ddfafc997e4f32c62c22490e439ac351cec827f436"
 "checksum unicode-bidi 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "49f2bd0c6468a8230e1db229cff8029217cf623c767ea5d60bfbd42729ea54d5"
diff --git a/node/runtime/wasm/build.sh b/node/runtime/wasm/build.sh
index 8cabead3fa539..b10d2628ae6ea 100755
--- a/node/runtime/wasm/build.sh
+++ b/node/runtime/wasm/build.sh
@@ -6,7 +6,7 @@ if cargo --version | grep -q "nightly"; then
 else
 	CARGO_CMD="cargo +nightly"
 fi
-$CARGO_CMD build --target=wasm32-unknown-unknown --release
+RUSTFLAGS="-C link-arg=--export-table" $CARGO_CMD build --target=wasm32-unknown-unknown --release
 for i in node_runtime
 do
 	wasm-gc target/wasm32-unknown-unknown/release/$i.wasm target/wasm32-unknown-unknown/release/$i.compact.wasm
diff --git a/node/runtime/wasm/target/wasm32-unknown-unknown/release/node_runtime.compact.wasm b/node/runtime/wasm/target/wasm32-unknown-unknown/release/node_runtime.compact.wasm
index cc77de34eb99e..5a68071a09395 100644
Binary files a/node/runtime/wasm/target/wasm32-unknown-unknown/release/node_runtime.compact.wasm and b/node/runtime/wasm/target/wasm32-unknown-unknown/release/node_runtime.compact.wasm differ