diff --git a/gio/gdbusproxy.c b/gio/gdbusproxy.c
index 542a8e8d2..af7638f3d 100644
--- a/gio/gdbusproxy.c
+++ b/gio/gdbusproxy.c
@@ -1701,12 +1701,12 @@ g_dbus_proxy_new_finish (GAsyncResult  *res,
  * g_dbus_proxy_new_sync:
  * @connection: A #GDBusConnection.
  * @flags: Flags used when constructing the proxy.
- * @info: A #GDBusInterfaceInfo specifying the minimal interface that @proxy conforms to or %NULL.
- * @name: A bus name (well-known or unique) or %NULL if @connection is not a message bus connection.
+ * @info: (allow-none): A #GDBusInterfaceInfo specifying the minimal interface that @proxy conforms to or %NULL.
+ * @name: (allow-none): A bus name (well-known or unique) or %NULL if @connection is not a message bus connection.
  * @object_path: An object path.
  * @interface_name: A D-Bus interface name.
- * @cancellable: A #GCancellable or %NULL.
- * @error: Return location for error or %NULL.
+ * @cancellable: (allow-none): A #GCancellable or %NULL.
+ * @error: (allow-none): Return location for error or %NULL.
  *
  * Creates a proxy for accessing @interface_name on the remote object
  * at @object_path owned by @name at @connection and synchronously