diff --git a/substrate/core/sr-primitives/src/generic/unchecked_extrinsic.rs b/substrate/core/sr-primitives/src/generic/unchecked_extrinsic.rs
index af3749c3f9..25661031e6 100644
--- a/substrate/core/sr-primitives/src/generic/unchecked_extrinsic.rs
+++ b/substrate/core/sr-primitives/src/generic/unchecked_extrinsic.rs
@@ -94,7 +94,7 @@ where
 				let payload = (index, self.function);
 				let signed = context.lookup(signed)?;
 				if !crate::verify_encoded_lazy(&signature, &payload, &signed) {
-					return Err("bad signature in extrinsic")
+					return Err(crate::BAD_SIGNATURE)
 				}
 				CheckedExtrinsic {
 					signed: Some((signed, payload.0)),
diff --git a/substrate/core/sr-primitives/src/generic/unchecked_mortal_compact_extrinsic.rs b/substrate/core/sr-primitives/src/generic/unchecked_mortal_compact_extrinsic.rs
index 4e5d5e5309..3ffe7fae40 100644
--- a/substrate/core/sr-primitives/src/generic/unchecked_mortal_compact_extrinsic.rs
+++ b/substrate/core/sr-primitives/src/generic/unchecked_mortal_compact_extrinsic.rs
@@ -95,7 +95,7 @@ where
 						signature.verify(payload, &signed)
 					}
 				}) {
-					return Err("bad signature in extrinsic")
+					return Err(crate::BAD_SIGNATURE)
 				}
 				CheckedExtrinsic {
 					signed: Some((signed, (raw_payload.0).0)),
@@ -255,7 +255,7 @@ mod tests {
 	fn badly_signed_check_should_fail() {
 		let ux = Ex::new_signed(0, vec![0u8;0], DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, vec![0u8]), Era::immortal());
 		assert!(ux.is_signed().unwrap_or(false));
-		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err("bad signature in extrinsic"));
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err(crate::BAD_SIGNATURE));
 	}
 
 	#[test]
@@ -283,14 +283,14 @@ mod tests {
 	fn too_late_mortal_signed_check_should_fail() {
 		let ux = Ex::new_signed(0, vec![0u8;0], DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, (DUMMY_ACCOUNTID, vec![0u8;0], Era::mortal(32, 10), 10u64).encode()), Era::mortal(32, 10));
 		assert!(ux.is_signed().unwrap_or(false));
-		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err("bad signature in extrinsic"));
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err(crate::BAD_SIGNATURE));
 	}
 
 	#[test]
 	fn too_early_mortal_signed_check_should_fail() {
 		let ux = Ex::new_signed(0, vec![0u8;0], DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, (DUMMY_ACCOUNTID, vec![0u8;0], Era::mortal(32, 43), 43u64).encode()), Era::mortal(32, 43));
 		assert!(ux.is_signed().unwrap_or(false));
-		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err("bad signature in extrinsic"));
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err(crate::BAD_SIGNATURE));
 	}
 
 	#[test]
diff --git a/substrate/core/sr-primitives/src/generic/unchecked_mortal_extrinsic.rs b/substrate/core/sr-primitives/src/generic/unchecked_mortal_extrinsic.rs
index 8ae6cc88b9..06c9003e33 100644
--- a/substrate/core/sr-primitives/src/generic/unchecked_mortal_extrinsic.rs
+++ b/substrate/core/sr-primitives/src/generic/unchecked_mortal_extrinsic.rs
@@ -95,7 +95,7 @@ where
 						signature.verify(payload, &signed)
 					}
 				}) {
-					return Err("bad signature in extrinsic")
+					return Err(crate::BAD_SIGNATURE)
 				}
 				CheckedExtrinsic {
 					signed: Some((signed, raw_payload.0)),
@@ -254,7 +254,7 @@ mod tests {
 	fn badly_signed_check_should_fail() {
 		let ux = Ex::new_signed(0, vec![0u8;0], DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, vec![0u8]), Era::immortal());
 		assert!(ux.is_signed().unwrap_or(false));
-		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err("bad signature in extrinsic"));
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err(crate::BAD_SIGNATURE));
 	}
 
 	#[test]
@@ -282,14 +282,14 @@ mod tests {
 	fn too_late_mortal_signed_check_should_fail() {
 		let ux = Ex::new_signed(0, vec![0u8;0], DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, (DUMMY_ACCOUNTID, vec![0u8;0], Era::mortal(32, 10), 10u64).encode()), Era::mortal(32, 10));
 		assert!(ux.is_signed().unwrap_or(false));
-		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err("bad signature in extrinsic"));
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err(crate::BAD_SIGNATURE));
 	}
 
 	#[test]
 	fn too_early_mortal_signed_check_should_fail() {
 		let ux = Ex::new_signed(0, vec![0u8;0], DUMMY_ACCOUNTID, TestSig(DUMMY_ACCOUNTID, (DUMMY_ACCOUNTID, vec![0u8;0], Era::mortal(32, 43), 43u64).encode()), Era::mortal(32, 43));
 		assert!(ux.is_signed().unwrap_or(false));
-		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err("bad signature in extrinsic"));
+		assert_eq!(<Ex as Checkable<TestContext>>::check(ux, &TestContext), Err(crate::BAD_SIGNATURE));
 	}
 
 	#[test]
diff --git a/substrate/core/sr-primitives/src/lib.rs b/substrate/core/sr-primitives/src/lib.rs
index d63f743fa2..93162a6ea8 100644
--- a/substrate/core/sr-primitives/src/lib.rs
+++ b/substrate/core/sr-primitives/src/lib.rs
@@ -43,6 +43,9 @@ pub mod traits;
 pub mod generic;
 pub mod transaction_validity;
 
+/// A message indicating an invalid signature in extrinsic.
+pub const BAD_SIGNATURE: &str = "bad signature in extrinsic";
+
 /// Full block error message.
 ///
 /// This allows modules to indicate that given transaction is potentially valid
diff --git a/substrate/core/test-runtime/src/lib.rs b/substrate/core/test-runtime/src/lib.rs
index 024532fbfb..f833c8318f 100644
--- a/substrate/core/test-runtime/src/lib.rs
+++ b/substrate/core/test-runtime/src/lib.rs
@@ -104,10 +104,10 @@ impl BlindCheckable for Extrinsic {
 		match self {
 			Extrinsic::AuthoritiesChange(new_auth) => Ok(Extrinsic::AuthoritiesChange(new_auth)),
 			Extrinsic::Transfer(transfer, signature) => {
-				if ::runtime_primitives::verify_encoded_lazy(&signature, &transfer, &transfer.from) {
+				if runtime_primitives::verify_encoded_lazy(&signature, &transfer, &transfer.from) {
 					Ok(Extrinsic::Transfer(transfer, signature))
 				} else {
-					Err("bad signature")
+					Err(runtime_primitives::BAD_SIGNATURE)
 				}
 			},
 		}
diff --git a/substrate/core/test-runtime/wasm/target/wasm32-unknown-unknown/release/substrate_test_runtime.compact.wasm b/substrate/core/test-runtime/wasm/target/wasm32-unknown-unknown/release/substrate_test_runtime.compact.wasm
index 5a4170542a..8e2be26970 100644
Binary files a/substrate/core/test-runtime/wasm/target/wasm32-unknown-unknown/release/substrate_test_runtime.compact.wasm and b/substrate/core/test-runtime/wasm/target/wasm32-unknown-unknown/release/substrate_test_runtime.compact.wasm differ
diff --git a/substrate/node/runtime/wasm/target/wasm32-unknown-unknown/release/node_runtime.compact.wasm b/substrate/node/runtime/wasm/target/wasm32-unknown-unknown/release/node_runtime.compact.wasm
index 3892ca679a..0e77e95a5a 100644
Binary files a/substrate/node/runtime/wasm/target/wasm32-unknown-unknown/release/node_runtime.compact.wasm and b/substrate/node/runtime/wasm/target/wasm32-unknown-unknown/release/node_runtime.compact.wasm differ
diff --git a/substrate/srml/executive/src/lib.rs b/substrate/srml/executive/src/lib.rs
index 725d5149a6..70318a65f4 100644
--- a/substrate/srml/executive/src/lib.rs
+++ b/substrate/srml/executive/src/lib.rs
@@ -254,7 +254,7 @@ impl<
 			Err("invalid account index") => return TransactionValidity::Unknown(INVALID_INDEX),
 			// Technically a bad signature could also imply an out-of-date account index, but
 			// that's more of an edge case.
-			Err("bad signature") => return TransactionValidity::Invalid(ApplyError::BadSignature as i8),
+			Err(primitives::BAD_SIGNATURE) => return TransactionValidity::Invalid(ApplyError::BadSignature as i8),
 			Err(_) => return TransactionValidity::Invalid(UNKNOWN_ERROR),
 		};