diff --git a/scripts/qapi/visit.py b/scripts/qapi/visit.py
index e3467b770b..678109dfb5 100644
--- a/scripts/qapi/visit.py
+++ b/scripts/qapi/visit.py
@@ -234,6 +234,9 @@ void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error
     default:
         error_setg(&err, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
                    "%(name)s");
+        /* Avoid passing invalid *obj to qapi_free_%(c_name)s() */
+        g_free(*obj);
+        *obj = NULL;
     }
 out_obj:
     visit_end_alternate(v, (void **)obj);