diff --git a/substrate/Cargo.lock b/substrate/Cargo.lock
index bf903c9e45..8291eb6d15 100644
--- a/substrate/Cargo.lock
+++ b/substrate/Cargo.lock
@@ -991,6 +991,7 @@ dependencies = [
  "byteorder 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "hex-literal 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "native-runtime 0.1.0",
  "parity-wasm 0.15.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "polkadot-primitives 0.1.0",
diff --git a/substrate/executor/Cargo.toml b/substrate/executor/Cargo.toml
index 18e7aa61bc..0e535f1eba 100644
--- a/substrate/executor/Cargo.toml
+++ b/substrate/executor/Cargo.toml
@@ -17,6 +17,7 @@ native-runtime = { path = "../native-runtime", version = "0.1" }
 runtime-std = { path = "../native-runtime/std", version = "0.1" }
 triehash = "0.1.0"
 hex-literal = "0.1.0"
+log = "0.3"
 
 [dev-dependencies]
 assert_matches = "1.1"
diff --git a/substrate/executor/src/lib.rs b/substrate/executor/src/lib.rs
index f82518f03b..d93f46052a 100644
--- a/substrate/executor/src/lib.rs
+++ b/substrate/executor/src/lib.rs
@@ -37,6 +37,7 @@ extern crate rustc_hex;
 extern crate native_runtime;
 extern crate runtime_std;
 extern crate triehash;
+#[macro_use] extern crate log;
 
 #[cfg(test)]
 #[macro_use]
diff --git a/substrate/executor/src/wasm_executor.rs b/substrate/executor/src/wasm_executor.rs
index 5ab95c3648..c4ed861ffb 100644
--- a/substrate/executor/src/wasm_executor.rs
+++ b/substrate/executor/src/wasm_executor.rs
@@ -94,17 +94,17 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 	ext_print_utf8(utf8_data: *const u8, utf8_len: u32) => {
 		if let Ok(utf8) = this.memory.get(utf8_data, utf8_len as usize) {
 			if let Ok(message) = String::from_utf8(utf8) {
-				println!("Runtime: {}", message);
+				info!(target: "runtime", "{}", message);
 			}
 		}
 	},
 	ext_print_hex(data: *const u8, len: u32) => {
 		if let Ok(hex) = this.memory.get(data, len as usize) {
-			println!("Runtime: {}", HexDisplay::from(&hex));
+			info!(target: "runtime", "{}", HexDisplay::from(&hex));
 		}
 	},
 	ext_print_num(number: u64) => {
-		println!("Runtime: {}", number);
+		info!(target: "runtime", "{}", number);
 	},
 	ext_memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 => {
 		let sl1 = this.memory.get(s1, n as usize).map_err(|_| DummyUserError)?;
@@ -145,7 +145,7 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 	ext_set_storage(key_data: *const u8, key_len: u32, value_data: *const u8, value_len: u32) => {
 		let key = this.memory.get(key_data, key_len as usize).map_err(|_| DummyUserError)?;
 		let value = this.memory.get(value_data, value_len as usize).map_err(|_| DummyUserError)?;
-		println!("Runtime: Setting storage: {} -> {}", HexDisplay::from(&key), HexDisplay::from(&value));
+		info!(target: "runtime", "Setting storage: {} -> {}", HexDisplay::from(&key), HexDisplay::from(&value));
 		this.ext.set_storage(key, value);
 	},
 	ext_get_allocated_storage(key_data: *const u8, key_len: u32, written_out: *mut u32) -> *mut u8 => {
@@ -161,7 +161,7 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 	ext_get_storage_into(key_data: *const u8, key_len: u32, value_data: *mut u8, value_len: u32, value_offset: u32) -> u32 => {
 		let key = this.memory.get(key_data, key_len as usize).map_err(|_| DummyUserError)?;
 		let value = this.ext.storage(&key).map_err(|_| DummyUserError)?;
-		println!("Runtime: Getting storage: {} ( -> {})", HexDisplay::from(&key), HexDisplay::from(&value));
+		info!(target: "runtime", "Getting storage: {} ( -> {})", HexDisplay::from(&key), HexDisplay::from(&value));
 		let value = &value[value_offset as usize..];
 		let written = ::std::cmp::min(value_len as usize, value.len());
 		this.memory.set(value_data, &value[..written]).map_err(|_| DummyUserError)?;
@@ -190,15 +190,15 @@ impl_function_executor!(this: FunctionExecutor<'e, E>,
 	},
 	ext_twox_128(data: *const u8, len: u32, out: *mut u8) => {
 		let result = if len == 0 {
-			println!("Runtime: XXhash: ''");
+			info!(target: "runtime", "XXhash: ''");
 			twox_128(&[0u8; 0])
 		} else {
 			let key = this.memory.get(data, len as usize).map_err(|_| DummyUserError)?;
 			let hashed_key = twox_128(&key);
 			if let Ok(skey) = ::std::str::from_utf8(&key) {
-				println!("Runtime: XXhash: {} -> {}", skey, HexDisplay::from(&hashed_key));
+				info!(target: "runtime", "XXhash: {} -> {}", skey, HexDisplay::from(&hashed_key));
 			} else {
-				println!("Runtime: XXhash: {} -> {}", HexDisplay::from(&key), HexDisplay::from(&hashed_key));
+				info!(target: "runtime", "XXhash: {} -> {}", HexDisplay::from(&key), HexDisplay::from(&hashed_key));
 			}
 			hashed_key
 		};