diff --git a/gdk/gdkinternals.h b/gdk/gdkinternals.h
index 6b179be033..9e2446948f 100644
--- a/gdk/gdkinternals.h
+++ b/gdk/gdkinternals.h
@@ -312,8 +312,6 @@ void       _gdk_window_process_updates_recurse (GdkWindow *window,
 
 void       _gdk_screen_close             (GdkScreen      *screen);
 
-const char *_gdk_get_sm_client_id (void);
-
 /*****************************************
  * Interfaces provided by windowing code *
  *****************************************/
diff --git a/gdk/gdkwindow.h b/gdk/gdkwindow.h
index 164281dc3c..f7ac2a5ded 100644
--- a/gdk/gdkwindow.h
+++ b/gdk/gdkwindow.h
@@ -676,7 +676,6 @@ void gdk_window_set_urgency_hint      (GdkWindow *window,
 void          gdk_window_set_geometry_hints (GdkWindow          *window,
 					     const GdkGeometry  *geometry,
 					     GdkWindowHints      geom_mask);
-void          gdk_set_sm_client_id          (const gchar        *sm_client_id);
 
 cairo_region_t *gdk_window_get_clip_region  (GdkWindow          *window);
 cairo_region_t *gdk_window_get_visible_region(GdkWindow         *window);