diff --git a/libs/remix-debug/src/solidity-decoder/types/RefType.ts b/libs/remix-debug/src/solidity-decoder/types/RefType.ts
index 299c4f8d6a..3e51915077 100644
--- a/libs/remix-debug/src/solidity-decoder/types/RefType.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/RefType.ts
@@ -89,7 +89,7 @@ export class RefType {
     } else {
       return {
         value: value.toString(),
-        type: type.underlyingType.typeName
+        type: (type.underlyingType && type.underlyingType.typeName) || type.typeName
       }
     }
   }