diff --git a/packages/contracts-periphery/contracts/testing/helpers/TestERC1271Wallet.sol b/packages/contracts-periphery/contracts/testing/helpers/TestERC1271Wallet.sol
index 302350d0a8d046849d0690dd0403577cf8b5ee80..84b4e51591348d87a2afd72b5eccf9f8382a9887 100644
--- a/packages/contracts-periphery/contracts/testing/helpers/TestERC1271Wallet.sol
+++ b/packages/contracts-periphery/contracts/testing/helpers/TestERC1271Wallet.sol
@@ -7,6 +7,7 @@ import { ECDSA } from "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
 
 /**
  * Simple ERC1271 wallet that can be used to test the ERC1271 signature checker.
+ * https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/mocks/ERC1271WalletMock.sol
  */
 
 contract TestERC1271Wallet is Ownable, IERC1271 {