diff --git a/gdk/quartz/gdkevents-quartz.c b/gdk/quartz/gdkevents-quartz.c
index 9cbfdda8e6..2520d4fa25 100644
--- a/gdk/quartz/gdkevents-quartz.c
+++ b/gdk/quartz/gdkevents-quartz.c
@@ -1393,14 +1393,6 @@ gdk_display_add_client_message_filter (GdkDisplay   *display,
   /* Not supported. */
 }
 
-void
-gdk_add_client_message_filter (GdkAtom       message_type,
-			       GdkFilterFunc func,
-			       gpointer      data)
-{
-  /* Not supported. */
-}
-
 void
 gdk_display_sync (GdkDisplay *display)
 {
diff --git a/gdk/win32/gdkevents-win32.c b/gdk/win32/gdkevents-win32.c
index e29df5538f..78d6cbe623 100644
--- a/gdk/win32/gdkevents-win32.c
+++ b/gdk/win32/gdkevents-win32.c
@@ -567,15 +567,6 @@ gdk_display_add_client_message_filter (GdkDisplay   *display,
 				       GdkAtom       message_type,
 				       GdkFilterFunc func,
 				       gpointer      data)
-{
-  /* XXX */
-  gdk_add_client_message_filter (message_type, func, data);
-}
-
-void
-gdk_add_client_message_filter (GdkAtom       message_type,
-			       GdkFilterFunc func,
-			       gpointer      data)
 {
   GdkClientFilter *filter = g_new (GdkClientFilter, 1);