diff --git a/qom/object.c b/qom/object.c
index 9edc06d391..c3d657e6cb 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -1197,7 +1197,8 @@ GSList *object_class_get_list(const char *implements_type,
     return list;
 }
 
-static gint object_class_cmp(gconstpointer a, gconstpointer b)
+static gint object_class_cmp(gconstpointer a, gconstpointer b,
+                             gpointer user_data)
 {
     return strcasecmp(object_class_get_name((ObjectClass *)a),
                       object_class_get_name((ObjectClass *)b));
@@ -1207,7 +1208,7 @@ GSList *object_class_get_list_sorted(const char *implements_type,
                                      bool include_abstract)
 {
     return g_slist_sort(object_class_get_list(implements_type, include_abstract),
-                        object_class_cmp);
+                        (GCompareFunc)object_class_cmp);
 }
 
 Object *object_ref(void *objptr)