diff --git a/substrate/executor/src/native_executor.rs b/substrate/executor/src/native_executor.rs
index 5e588d559c..28146a46ea 100644
--- a/substrate/executor/src/native_executor.rs
+++ b/substrate/executor/src/native_executor.rs
@@ -1,6 +1,7 @@
 use primitives::contract::CallData;
 use state_machine::{Externalities, CodeExecutor};
 use error::{Error, ErrorKind, Result};
+use wasm_executor::WasmExecutor;
 use native_runtime as runtime;
 use runtime_support;
 
@@ -22,13 +23,13 @@ impl CodeExecutor for NativeExecutor {
 		if code == &native_equivalent[..] {
 			runtime_support::with_externalities(ext, || match method {
 				// TODO: Panic handler that comes back with error.
-				"execute_block" => Ok(runtime::execute_block(data.0)),
-				"execute_transaction" => Ok(runtime::execute_transaction(data.0)),
+				"execute_block" => Ok(runtime::execute_block(&data.0)),
+				"execute_transaction" => Ok(runtime::execute_transaction(&data.0)),
 				_ => Err(ErrorKind::MethodNotFound(method.to_owned()).into()),
 			})
 		} else {
 			// call into wasm.
-			unimplemented!()
+			WasmExecutor.call(ext, code, method, data)
 		}
 	}
 }
diff --git a/substrate/native-runtime/support/src/lib.rs b/substrate/native-runtime/support/src/lib.rs
index 68914423b5..448cb6ce20 100644
--- a/substrate/native-runtime/support/src/lib.rs
+++ b/substrate/native-runtime/support/src/lib.rs
@@ -42,7 +42,7 @@ impl fmt::Display for NoError {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "") }
 }
 
-environmental!(ext : Externalities + 'static);
+environmental!(ext : trait Externalities);
 
 /// Get `key` from storage and return a `Vec`, empty if there's a problem.
 pub fn storage(key: &[u8]) -> Vec<u8> {
@@ -93,7 +93,7 @@ pub fn ed25519_verify(sig: &[u8; 64], msg: &[u8], pubkey: &[u8; 32]) -> bool {
 
 /// Execute the given closure with global function available whose functionality routes into the
 /// externalities `ext`. Forwards the value that the closure returns.
-pub fn with_externalities<R, F: FnOnce() -> R>(ext: &mut (Externalities + 'static), f: F) -> R {
+pub fn with_externalities<R, F: FnOnce() -> R>(ext: &mut Externalities, f: F) -> R {
 	ext::using(ext, f)
 }
 
diff --git a/substrate/wasm-runtime/polkadot/src/lib.rs b/substrate/wasm-runtime/polkadot/src/lib.rs
index 713d8eb091..66c5c866f6 100644
--- a/substrate/wasm-runtime/polkadot/src/lib.rs
+++ b/substrate/wasm-runtime/polkadot/src/lib.rs
@@ -40,14 +40,14 @@ use primitives::{Block, UncheckedTransaction};
 
 /// Execute a block, with `input` being the canonical serialisation of the block. Returns the
 /// empty vector.
-pub fn execute_block(input: Vec<u8>) -> Vec<u8> {
-	runtime::system::execute_block(Block::from_slice(&input).unwrap());
+pub fn execute_block(input: &[u8]) -> Vec<u8> {
+	runtime::system::execute_block(Block::from_slice(input).unwrap());
 	Vec::new()
 }
 
 /// Execute a given, serialised, transaction. Returns the empty vector.
-pub fn execute_transaction(input: Vec<u8>) -> Vec<u8> {
-	runtime::system::execute_transaction(&UncheckedTransaction::from_slice(&input).unwrap());
+pub fn execute_transaction(input: &[u8]) -> Vec<u8> {
+	runtime::system::execute_transaction(&UncheckedTransaction::from_slice(input).unwrap());
 	Vec::new()
 }
 
diff --git a/substrate/wasm-runtime/support/src/lib.rs b/substrate/wasm-runtime/support/src/lib.rs
index 4d96617a8a..a01fe17c26 100644
--- a/substrate/wasm-runtime/support/src/lib.rs
+++ b/substrate/wasm-runtime/support/src/lib.rs
@@ -135,7 +135,7 @@ macro_rules! impl_stubs {
 						$crate::Vec::from_raw_parts(input_data, input_len, input_len)
 					};
 
-					let output = super::$name(input);
+					let output = super::$name(&input[..]);
 					&output[0] as *const u8 as u64 + ((output.len() as u64) << 32)
 				}
 			)*
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 ceac1b036e..fbac14afd6 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 4a56fe2760..2af80d0b4a 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 5c717847a5..34ed540db2 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 64fb6a48bf..4ec976b958 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
diff --git a/substrate/wasm-runtime/test/src/lib.rs b/substrate/wasm-runtime/test/src/lib.rs
index 1cf1934976..6e257a091f 100644
--- a/substrate/wasm-runtime/test/src/lib.rs
+++ b/substrate/wasm-runtime/test/src/lib.rs
@@ -10,26 +10,26 @@ use alloc::vec::Vec;
 extern crate runtime_support;
 use runtime_support::{set_storage, storage, print, blake2_256, twox_128, twox_256, ed25519_verify};
 
-fn test_blake2_256(input: Vec<u8>) -> Vec<u8> {
+fn test_blake2_256(input: &[u8]) -> Vec<u8> {
 	blake2_256(&input).to_vec()
 }
 
-fn test_twox_256(input: Vec<u8>) -> Vec<u8> {
+fn test_twox_256(input: &[u8]) -> Vec<u8> {
 	twox_256(&input).to_vec()
 }
 
-fn test_twox_128(input: Vec<u8>) -> Vec<u8> {
+fn test_twox_128(input: &[u8]) -> Vec<u8> {
 	twox_128(&input).to_vec()
 }
 
-fn test_ed25519_verify(input: Vec<u8>) -> Vec<u8> {
+fn test_ed25519_verify(input: &[u8]) -> Vec<u8> {
 	let sig = &input[0..64];
 	let pubkey = &input[64..96];
 	let msg = b"all ok!";
 	[ed25519_verify(sig, &msg[..], pubkey) as u8].to_vec()
 }
 
-fn test_data_in(input: Vec<u8>) -> Vec<u8> {
+fn test_data_in(input: &[u8]) -> Vec<u8> {
 	print(b"set_storage" as &[u8]);
 	set_storage(b"input", &input);