diff --git a/Objects/unionobject.c b/Objects/unionobject.c
index 98db27d..229b518 100644
--- a/Objects/unionobject.c
+++ b/Objects/unionobject.c
@@ -124,7 +124,7 @@ is_typing_name(PyObject *obj, char *name)
     if (strcmp(type->tp_name, name) != 0) {
         return 0;
     }
-    return is_typing_module(obj);
+    return is_typing_module((PyObject *)type);
 }
 
 static PyObject *