diff --git a/contracts/colony/ColonyStorage.sol b/contracts/colony/ColonyStorage.sol
index fd714d08e5..68189ed074 100755
--- a/contracts/colony/ColonyStorage.sol
+++ b/contracts/colony/ColonyStorage.sol
@@ -239,7 +239,7 @@ contract ColonyStorage is CommonStorage, ColonyDataTypes, ColonyNetworkDataTypes
   }
 
   modifier onlyOwnExtension() {
-    require(isOwnExtension(msg.sender), "colony-must-be-extension");
+    require(isOwnExtension(msg.sender), "colony-must-be-own-extension");
     _;
   }
 
diff --git a/test/contracts-network/colony-network-extensions.js b/test/contracts-network/colony-network-extensions.js
index 9e89c309ef..d13cf0273e 100644
--- a/test/contracts-network/colony-network-extensions.js
+++ b/test/contracts-network/colony-network-extensions.js
@@ -324,13 +324,13 @@ contract("Colony Network Extensions", (accounts) => {
     it("does not allow non network-managed extensions to lock and unlock tokens", async () => {
       const testVotingToken = await TestVotingToken.new();
       await testVotingToken.install(colony.address);
-      await checkErrorRevert(testVotingToken.lockToken(), "colony-must-be-extension");
-      await checkErrorRevert(testVotingToken.unlockTokenForUser(ROOT, 0), "colony-must-be-extension");
+      await checkErrorRevert(testVotingToken.lockToken(), "colony-must-be-own-extension");
+      await checkErrorRevert(testVotingToken.unlockTokenForUser(ROOT, 0), "colony-must-be-own-extension");
     });
 
     it("does not allow users to lock and unlock tokens", async () => {
-      await checkErrorRevert(colony.lockToken(), "colony-sender-must-be-contract");
-      await checkErrorRevert(colony.unlockTokenForUser(ROOT, 0), "colony-sender-must-be-contract");
+      await checkErrorRevert(colony.lockToken(), "colony-must-be-own-extension");
+      await checkErrorRevert(colony.unlockTokenForUser(ROOT, 0), "colony-must-be-own-extension");
     });
 
     it("does not allow a colony to unlock a lock placed by another colony", async () => {