diff --git a/substrate/Cargo.lock b/substrate/Cargo.lock
index c741c845a5..3b715cee8d 100644
--- a/substrate/Cargo.lock
+++ b/substrate/Cargo.lock
@@ -553,6 +553,7 @@ dependencies = [
 name = "native-runtime"
 version = "0.1.0"
 dependencies = [
+ "polkadot-runtime-codec 0.1.0",
  "runtime-std 0.1.0",
  "rustc-hex 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -730,6 +731,7 @@ dependencies = [
  "native-runtime 0.1.0",
  "parity-wasm 0.15.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "polkadot-primitives 0.1.0",
+ "polkadot-runtime-codec 0.1.0",
  "polkadot-serializer 0.1.0",
  "polkadot-state-machine 0.1.0",
  "runtime-std 0.1.0",
@@ -780,6 +782,10 @@ dependencies = [
  "polkadot-rpc 0.1.0",
 ]
 
+[[package]]
+name = "polkadot-runtime-codec"
+version = "0.1.0"
+
 [[package]]
 name = "polkadot-serializer"
 version = "0.1.0"
diff --git a/substrate/Cargo.toml b/substrate/Cargo.toml
index 21232d39ef..f01f860386 100644
--- a/substrate/Cargo.toml
+++ b/substrate/Cargo.toml
@@ -18,6 +18,7 @@ members = [
 	"rpc",
 	"rpc_servers",
 	"native-runtime",
+	"runtime-codec",
 	"serializer",
 	"state_machine",
 	"validator",
diff --git a/substrate/executor/Cargo.toml b/substrate/executor/Cargo.toml
index 5329eb7023..f27f7e2b26 100644
--- a/substrate/executor/Cargo.toml
+++ b/substrate/executor/Cargo.toml
@@ -5,6 +5,7 @@ authors = ["Parity Technologies <admin@parity.io>"]
 
 [dependencies]
 error-chain = "0.11"
+polkadot-runtime-codec = { path = "../runtime-codec", version = "0.1" }
 polkadot-primitives = { path = "../primitives", version = "0.1" }
 polkadot-serializer = { path = "../serializer", version = "0.1" }
 polkadot-state-machine = { path = "../state_machine" , version = "0.1" }
diff --git a/substrate/executor/src/lib.rs b/substrate/executor/src/lib.rs
index 9935f8aec8..10684b1531 100644
--- a/substrate/executor/src/lib.rs
+++ b/substrate/executor/src/lib.rs
@@ -27,6 +27,7 @@
 
 #![warn(missing_docs)]
 
+extern crate polkadot_runtime_codec as codec;
 extern crate polkadot_primitives as primitives;
 extern crate polkadot_serializer as serializer;
 extern crate polkadot_state_machine as state_machine;
diff --git a/substrate/executor/src/native_executor.rs b/substrate/executor/src/native_executor.rs
index b8c90f2d9a..d47719662c 100644
--- a/substrate/executor/src/native_executor.rs
+++ b/substrate/executor/src/native_executor.rs
@@ -41,8 +41,8 @@ impl CodeExecutor for NativeExecutor {
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use native_runtime::codec::KeyedVec;
-	use native_runtime::support::{TestExternalities, one, two, StaticHexInto};
+	use codec::KeyedVec;
+	use native_runtime::support::{one, two, TestExternalities, StaticHexInto};
 	use native_runtime::runtime::staking::balance;
 	use primitives::twox_128;
 
diff --git a/substrate/executor/src/wasm_executor.rs b/substrate/executor/src/wasm_executor.rs
index 439defd449..01601ac379 100644
--- a/substrate/executor/src/wasm_executor.rs
+++ b/substrate/executor/src/wasm_executor.rs
@@ -280,8 +280,8 @@ mod tests {
 	use rustc_hex::FromHex;
 	use primitives::{blake2_256, twox_128};
 	use runtime_std;
+	use codec::KeyedVec;
 	use native_runtime::support::{one, two, StaticHexInto, TestExternalities};
-	use native_runtime::codec::KeyedVec;
 	use native_runtime::runtime::staking::balance;
 
 	#[test]
diff --git a/substrate/native-runtime/Cargo.toml b/substrate/native-runtime/Cargo.toml
index 25091c2cef..60dbbe19c6 100644
--- a/substrate/native-runtime/Cargo.toml
+++ b/substrate/native-runtime/Cargo.toml
@@ -3,11 +3,12 @@ name = "native-runtime"
 version = "0.1.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 
+[dependencies]
+polkadot-runtime-codec = { path = "../runtime-codec", version = "0.1" }
+runtime-std = { path = "./std", version = "0.1" }
+rustc-hex = "1.0"
+
 [features]
 default = ["with-std"]
 with-std = []
-without-std = []
-
-[dependencies]
-runtime-std = { path = "./std", version = "0.1" }
-rustc-hex = "1.0"
+without-std = ["polkadot-runtime-codec/no-std"]
diff --git a/substrate/runtime-codec/Cargo.toml b/substrate/runtime-codec/Cargo.toml
new file mode 100644
index 0000000000..3221a55802
--- /dev/null
+++ b/substrate/runtime-codec/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "polkadot-runtime-codec"
+description = "Serialization and deserialization codec for runtime values"
+version = "0.1.0"
+authors = ["Parity Technologies <admin@parity.io>"]
+
+[dependencies]
+
+[features]
+no-std = []
+default = []
diff --git a/substrate/wasm-runtime/polkadot/src/codec/endiansensitive.rs b/substrate/runtime-codec/src/endiansensitive.rs
similarity index 100%
rename from substrate/wasm-runtime/polkadot/src/codec/endiansensitive.rs
rename to substrate/runtime-codec/src/endiansensitive.rs
diff --git a/substrate/wasm-runtime/polkadot/src/codec/joiner.rs b/substrate/runtime-codec/src/joiner.rs
similarity index 69%
rename from substrate/wasm-runtime/polkadot/src/codec/joiner.rs
rename to substrate/runtime-codec/src/joiner.rs
index a7a9f618eb..1d19851243 100644
--- a/substrate/wasm-runtime/polkadot/src/codec/joiner.rs
+++ b/substrate/runtime-codec/src/joiner.rs
@@ -14,19 +14,20 @@
 // You should have received a copy of the GNU General Public License
 // along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Vec<u8> serialiser.
+//! Trait
 
-use runtime_std::prelude::*;
+use std::iter::Extend;
 use super::slicable::Slicable;
 
-/// Trait to allow itself to be serialised into a `Vec<u8>`
+/// Trait to allow itself to be serialised into a value which can be extended
+/// by bytes.
 pub trait Joiner {
-	fn join<T: Slicable + Sized>(self, value: &T) -> Self;
+	fn join<V: Slicable + Sized>(self, value: &V) -> Self;
 }
 
-impl Joiner for Vec<u8> {
-	fn join<T: Slicable + Sized>(mut self, value: &T) -> Vec<u8> {
-		value.as_slice_then(|s| self.extend_from_slice(s));
+impl<T> Joiner for T where T: for<'a> Extend<&'a u8> {
+	fn join<V: Slicable + Sized>(mut self, value: &V) -> Self {
+		value.as_slice_then(|s| self.extend(s));
 		self
 	}
 }
diff --git a/substrate/wasm-runtime/polkadot/src/codec/keyedvec.rs b/substrate/runtime-codec/src/keyedvec.rs
similarity index 92%
rename from substrate/wasm-runtime/polkadot/src/codec/keyedvec.rs
rename to substrate/runtime-codec/src/keyedvec.rs
index 2c55cb5648..2b4bc99fbd 100644
--- a/substrate/wasm-runtime/polkadot/src/codec/keyedvec.rs
+++ b/substrate/runtime-codec/src/keyedvec.rs
@@ -16,8 +16,9 @@
 
 //! Serialiser and prepender.
 
-use runtime_std::prelude::*;
-use super::slicable::Slicable;
+use slicable::Slicable;
+use std::iter::Extend;
+use std::vec::Vec;
 
 /// Trait to allow itselg to be serialised and prepended by a given slice.
 pub trait KeyedVec {
@@ -29,7 +30,7 @@ macro_rules! impl_non_endians {
 		impl KeyedVec for $t {
 			fn to_keyed_vec(&self, prepend_key: &[u8]) -> Vec<u8> {
 				let mut r = prepend_key.to_vec();
-				r.extend_from_slice(&self[..]);
+				r.extend(&self[..]);
 				r
 			}
 		}
@@ -42,7 +43,7 @@ macro_rules! impl_endians {
 			fn to_keyed_vec(&self, prepend_key: &[u8]) -> Vec<u8> {
 				self.as_slice_then(|slice| {
 					let mut r = prepend_key.to_vec();
-					r.extend_from_slice(slice);
+					r.extend(slice);
 					r
 				})
 			}
diff --git a/substrate/wasm-runtime/polkadot/src/codec/mod.rs b/substrate/runtime-codec/src/lib.rs
similarity index 77%
rename from substrate/wasm-runtime/polkadot/src/codec/mod.rs
rename to substrate/runtime-codec/src/lib.rs
index 94afc574c1..060df4e95c 100644
--- a/substrate/wasm-runtime/polkadot/src/codec/mod.rs
+++ b/substrate/runtime-codec/src/lib.rs
@@ -14,7 +14,11 @@
 // You should have received a copy of the GNU General Public License
 // along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Codec utils.
+//! Implements the serialization and deserialization codec for polkadot runtime
+//! values.
+
+#![cfg_attr(feature = "no-std", no_std)]
+#![cfg_attr(feature = "no-std", feature(alloc))]
 
 mod endiansensitive;
 mod slicable;
@@ -27,3 +31,11 @@ pub use self::slicable::{Slicable, NonTrivialSlicable};
 pub use self::streamreader::StreamReader;
 pub use self::joiner::Joiner;
 pub use self::keyedvec::KeyedVec;
+
+#[cfg(feature = "no-std")]
+mod std {
+	extern crate alloc;
+
+	pub use core::*;
+	pub use self::alloc::vec;
+}
diff --git a/substrate/wasm-runtime/polkadot/src/codec/slicable.rs b/substrate/runtime-codec/src/slicable.rs
similarity index 88%
rename from substrate/wasm-runtime/polkadot/src/codec/slicable.rs
rename to substrate/runtime-codec/src/slicable.rs
index 0f1ef812a6..82b527c771 100644
--- a/substrate/wasm-runtime/polkadot/src/codec/slicable.rs
+++ b/substrate/runtime-codec/src/slicable.rs
@@ -16,15 +16,16 @@
 
 //! Serialisation.
 
-use runtime_std::prelude::*;
-use runtime_std::{mem, slice};
+use std::{mem, slice};
+use std::vec::Vec;
 use super::joiner::Joiner;
 use super::endiansensitive::EndianSensitive;
 
 /// Trait that allows zero-copy read/write of value-references to/from slices in LE format.
 pub trait Slicable: Sized {
+	/// Attempt to deserialise the value from a slice.
 	fn from_slice(value: &[u8]) -> Option<Self> {
-		Self::set_as_slice(&|out, offset| if value.len() >= out.len() + offset {
+		Self::set_as_slice(|out, offset| if value.len() >= out.len() + offset {
 			let value = &value[offset..];
 			let len = out.len();
 			out.copy_from_slice(&value[0..len]);
@@ -36,7 +37,7 @@ pub trait Slicable: Sized {
 	fn to_vec(&self) -> Vec<u8> {
 		self.as_slice_then(|s| s.to_vec())
 	}
-	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(set_slice: &F) -> Option<Self>;
+	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(fill_slice: F) -> Option<Self>;
 	fn as_slice_then<R, F: FnOnce(&[u8]) -> R>(&self, f: F) -> R {
 		f(&self.to_vec())
 	}
@@ -47,7 +48,7 @@ pub trait Slicable: Sized {
 pub trait NonTrivialSlicable: Slicable {}
 
 impl<T: EndianSensitive> Slicable for T {
-	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(fill_slice: &F) -> Option<Self> {
+	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(fill_slice: F) -> Option<Self> {
 		let size = mem::size_of::<T>();
 		assert!(size > 0, "EndianSensitive can never be implemented for a zero-sized type.");
 		let mut result: T = unsafe { mem::zeroed() };
@@ -81,8 +82,8 @@ impl Slicable for Vec<u8> {
 	fn from_slice(value: &[u8]) -> Option<Self> {
 		Some(value[4..].to_vec())
 	}
-	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(fill_slice: &F) -> Option<Self> {
-		u32::set_as_slice(fill_slice).and_then(|len| {
+	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(fill_slice: F) -> Option<Self> {
+		u32::set_as_slice(&fill_slice).and_then(|len| {
 			let mut v = Vec::with_capacity(len as usize);
 			unsafe { v.set_len(len as usize); }
 			if fill_slice(&mut v, 4) {
@@ -117,7 +118,7 @@ impl<T: NonTrivialSlicable> Slicable for Vec<T> {
 		Some(r)
 	}
 
-	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(_fill_slice: &F) -> Option<Self> {
+	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(_fill_slice: F) -> Option<Self> {
 		unimplemented!();
 	}
 
diff --git a/substrate/wasm-runtime/polkadot/src/codec/streamreader.rs b/substrate/runtime-codec/src/streamreader.rs
similarity index 98%
rename from substrate/wasm-runtime/polkadot/src/codec/streamreader.rs
rename to substrate/runtime-codec/src/streamreader.rs
index b745f8afd9..33056a5ac3 100644
--- a/substrate/wasm-runtime/polkadot/src/codec/streamreader.rs
+++ b/substrate/runtime-codec/src/streamreader.rs
@@ -16,7 +16,7 @@
 
 //! Deserialiser.
 
-use super::slicable::Slicable;
+use slicable::Slicable;
 
 /// Simple deserialiser.
 pub struct StreamReader<'a> {
diff --git a/substrate/wasm-runtime/Cargo.lock b/substrate/wasm-runtime/Cargo.lock
index 15ccc67c64..93bc305136 100644
--- a/substrate/wasm-runtime/Cargo.lock
+++ b/substrate/wasm-runtime/Cargo.lock
@@ -1,3 +1,7 @@
+[[package]]
+name = "polkadot-runtime-codec"
+version = "0.1.0"
+
 [[package]]
 name = "pwasm-alloc"
 version = "0.1.0"
@@ -13,6 +17,7 @@ version = "0.1.0"
 name = "runtime-polkadot"
 version = "0.1.0"
 dependencies = [
+ "polkadot-runtime-codec 0.1.0",
  "runtime-std 0.1.0",
 ]
 
diff --git a/substrate/wasm-runtime/polkadot/Cargo.toml b/substrate/wasm-runtime/polkadot/Cargo.toml
index 669ccac6fa..5cc45d4c01 100644
--- a/substrate/wasm-runtime/polkadot/Cargo.toml
+++ b/substrate/wasm-runtime/polkadot/Cargo.toml
@@ -7,9 +7,10 @@ authors = ["Parity Technologies <admin@parity.io>"]
 crate-type = ["cdylib"]
 
 [dependencies]
+polkadot-runtime-codec = { path = "../../runtime-codec", version = "0.1" }
 runtime-std = { path = "../std", version = "0.1" }
 
 [features]
 default = ["without-std"]
 with-std = []
-without-std = []
+without-std = ["polkadot-runtime-codec/no-std"]
diff --git a/substrate/wasm-runtime/polkadot/src/lib.rs b/substrate/wasm-runtime/polkadot/src/lib.rs
index 1eeff3c649..ceec42af21 100644
--- a/substrate/wasm-runtime/polkadot/src/lib.rs
+++ b/substrate/wasm-runtime/polkadot/src/lib.rs
@@ -17,7 +17,6 @@
 //! The Polkadot runtime. This can be compiled with #[no_std], ready for Wasm.
 
 #![cfg_attr(feature = "without-std", no_std)]
-#![cfg_attr(feature = "strict", deny(warnings))]
 
 #[macro_use]
 extern crate runtime_std;
@@ -25,7 +24,8 @@ extern crate runtime_std;
 #[cfg(feature = "with-std")]
 extern crate rustc_hex;
 
-pub mod codec;
+extern crate polkadot_runtime_codec as codec;
+
 #[macro_use]
 pub mod support;
 pub mod primitives;
diff --git a/substrate/wasm-runtime/polkadot/src/primitives/block.rs b/substrate/wasm-runtime/polkadot/src/primitives/block.rs
index d33b51609c..a884bcccec 100644
--- a/substrate/wasm-runtime/polkadot/src/primitives/block.rs
+++ b/substrate/wasm-runtime/polkadot/src/primitives/block.rs
@@ -38,7 +38,7 @@ impl Slicable for Block {
 		})
 	}
 
-	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(_fill_slice: &F) -> Option<Self> {
+	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(_fill_slice: F) -> Option<Self> {
 		unimplemented!();
 	}
 
diff --git a/substrate/wasm-runtime/polkadot/src/primitives/header.rs b/substrate/wasm-runtime/polkadot/src/primitives/header.rs
index c97d5ebf29..4c1ec328ea 100644
--- a/substrate/wasm-runtime/polkadot/src/primitives/header.rs
+++ b/substrate/wasm-runtime/polkadot/src/primitives/header.rs
@@ -49,7 +49,7 @@ impl Slicable for Header {
 		})
 	}
 
-	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(_fill_slice: &F) -> Option<Self> {
+	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(_fill_slice: F) -> Option<Self> {
 		unimplemented!();
 	}
 
diff --git a/substrate/wasm-runtime/polkadot/src/primitives/proposal.rs b/substrate/wasm-runtime/polkadot/src/primitives/proposal.rs
index 1b8aa6b13e..8eb050cf67 100644
--- a/substrate/wasm-runtime/polkadot/src/primitives/proposal.rs
+++ b/substrate/wasm-runtime/polkadot/src/primitives/proposal.rs
@@ -65,10 +65,10 @@ pub struct Proposal {
 }
 
 impl Slicable for Proposal {
-	fn set_as_slice<F: Fn(&mut[u8], usize) -> bool>(fill_slice: &F) -> Option<Self> {
+	fn set_as_slice<F: Fn(&mut[u8], usize) -> bool>(fill_slice: F) -> Option<Self> {
 		Some(Proposal {
-			function: InternalFunction::from_u8(Slicable::set_as_slice(fill_slice)?)?,
-			input_data: Slicable::set_as_slice(&|s, o| fill_slice(s, o + 1))?,
+			function: InternalFunction::from_u8(Slicable::set_as_slice(&fill_slice)?)?,
+			input_data: Slicable::set_as_slice(|s, o| fill_slice(s, o + 1))?,
 		})
 	}
 
diff --git a/substrate/wasm-runtime/polkadot/src/primitives/transaction.rs b/substrate/wasm-runtime/polkadot/src/primitives/transaction.rs
index 9c72e31d34..73ab9edd29 100644
--- a/substrate/wasm-runtime/polkadot/src/primitives/transaction.rs
+++ b/substrate/wasm-runtime/polkadot/src/primitives/transaction.rs
@@ -45,7 +45,7 @@ impl Slicable for Transaction {
 		})
 	}
 
-	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(_fill_slice: &F) -> Option<Self> {
+	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(_fill_slice: F) -> Option<Self> {
 		unimplemented!();
 	}
 
diff --git a/substrate/wasm-runtime/polkadot/src/primitives/uncheckedtransaction.rs b/substrate/wasm-runtime/polkadot/src/primitives/uncheckedtransaction.rs
index ec14befb55..83984e08a4 100644
--- a/substrate/wasm-runtime/polkadot/src/primitives/uncheckedtransaction.rs
+++ b/substrate/wasm-runtime/polkadot/src/primitives/uncheckedtransaction.rs
@@ -63,7 +63,7 @@ impl Slicable for UncheckedTransaction {
 		})
 	}
 
-	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(_fill_slice: &F) -> Option<Self> {
+	fn set_as_slice<F: Fn(&mut [u8], usize) -> bool>(_fill_slice: F) -> Option<Self> {
 		unimplemented!();
 	}
 
diff --git a/substrate/wasm-runtime/polkadot/src/support/storage.rs b/substrate/wasm-runtime/polkadot/src/support/storage.rs
index 3ff8b1c75d..bf9d605eb5 100644
--- a/substrate/wasm-runtime/polkadot/src/support/storage.rs
+++ b/substrate/wasm-runtime/polkadot/src/support/storage.rs
@@ -24,7 +24,7 @@ use codec::{Slicable, KeyedVec};
 
 /// Return the value of the item in storage under `key`, or `None` if there is no explicit entry.
 pub fn get<T: Slicable + Sized>(key: &[u8]) -> Option<T> {
-	Slicable::set_as_slice(&|out, offset|
+	Slicable::set_as_slice(|out, offset|
 		runtime_std::read_storage(&twox_128(key)[..], out, offset) >= out.len()
 	)
 }
diff --git a/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_polkadot.compact.wasm b/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_polkadot.compact.wasm
index db7dab9917..898f194e80 100644
Binary files a/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_polkadot.compact.wasm and b/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_polkadot.compact.wasm differ
diff --git a/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_polkadot.wasm b/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_polkadot.wasm
index a0dc5a2754..a4c416d6da 100644
Binary files a/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_polkadot.wasm and b/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_polkadot.wasm differ
diff --git a/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_test.compact.wasm b/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_test.compact.wasm
index 63e7666aad..a1127c4e66 100644
Binary files a/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_test.compact.wasm and b/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_test.compact.wasm differ
diff --git a/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_test.wasm b/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_test.wasm
index c1b257f3a3..f8244dc3a2 100644
Binary files a/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_test.wasm and b/substrate/wasm-runtime/target/wasm32-unknown-unknown/release/runtime_test.wasm differ