diff --git a/gdk/quartz/gdkwindow-quartz.c b/gdk/quartz/gdkwindow-quartz.c
index 75ef38534e..2b4b2cc709 100644
--- a/gdk/quartz/gdkwindow-quartz.c
+++ b/gdk/quartz/gdkwindow-quartz.c
@@ -376,7 +376,6 @@ _gdk_quartz_display_before_process_all_updates (GdkDisplay *display)
 void
 _gdk_quartz_display_after_process_all_updates (GdkDisplay *display)
 {
-  GSList *old_update_nswindows = update_nswindows;
   GSList *tmp_list = update_nswindows;
 
   update_nswindows = NULL;
@@ -391,11 +390,9 @@ _gdk_quartz_display_after_process_all_updates (GdkDisplay *display)
       [nswindow flushWindow];
       [nswindow release];
 
-      tmp_list = tmp_list->next;
+      tmp_list = g_slist_remove_link (tmp_list, tmp_list);
     }
 
-  g_slist_free (old_update_nswindows);
-
   in_process_all_updates = FALSE;
 
   NSEnableScreenUpdates ();