diff --git a/src/resource_append.cpp b/src/resource_append.cpp
index e1f7bbd..4ecc9b2 100644
--- a/src/resource_append.cpp
+++ b/src/resource_append.cpp
@@ -65,7 +65,7 @@ uint32_t ResourceAppend::Combine()
     }
 
     if (!ParseRef()) {
-        return false;
+        return RESTOOL_ERROR;
     }
 
     ResourceTable resourceTable;