diff --git a/gdk/x11/gdkscreen-x11.c b/gdk/x11/gdkscreen-x11.c
index 5b0cb17846..1d274f4ed5 100644
--- a/gdk/x11/gdkscreen-x11.c
+++ b/gdk/x11/gdkscreen-x11.c
@@ -234,7 +234,7 @@ gdk_screen_get_root_window (GdkScreen *screen)
  *
  * Gets the default colormap for @screen.
  * 
- * Returns: the default #GdkColormap.
+ * Returns: (transfer none): the default #GdkColormap.
  *
  * Since: 2.2
  **/