diff --git a/src/interfaces/ITIP20Factory.sol b/src/interfaces/ITIP20Factory.sol
index d1c24ea..9e69962 100644
--- a/src/interfaces/ITIP20Factory.sol
+++ b/src/interfaces/ITIP20Factory.sol
@@ -7,6 +7,7 @@ import {ITIP20} from "./ITIP20.sol";
 /// @notice Factory contract for creating and deploying TIP-20 compliant tokens
 interface ITIP20Factory {
     error AddressReserved();
+    error AddressNotReserved();
     error InvalidQuoteToken();
     error TokenAlreadyExists(address tokenAddress);