diff --git a/gdk/gdkdisplay.c b/gdk/gdkdisplay.c
index 34b6cab8ad..44e0f6c7de 100644
--- a/gdk/gdkdisplay.c
+++ b/gdk/gdkdisplay.c
@@ -1714,6 +1714,9 @@ gdk_display_supports_input_shapes (GdkDisplay *display)
  * Returns: %TRUE if windows may be composited.
  *
  * Since: 2.12
+ *
+ * Deprecated: 3.16: Compositing is an outdated technology that
+ *   only ever worked on X11.
  */
 gboolean
 gdk_display_supports_composite (GdkDisplay *display)
diff --git a/gdk/gdkdisplay.h b/gdk/gdkdisplay.h
index 5595cb9fb7..e82c533348 100644
--- a/gdk/gdkdisplay.h
+++ b/gdk/gdkdisplay.h
@@ -159,7 +159,7 @@ GDK_AVAILABLE_IN_ALL
 gboolean gdk_display_supports_shapes           (GdkDisplay    *display);
 GDK_AVAILABLE_IN_ALL
 gboolean gdk_display_supports_input_shapes     (GdkDisplay    *display);
-GDK_AVAILABLE_IN_ALL
+GDK_DEPRECATED_IN_3_16
 gboolean gdk_display_supports_composite        (GdkDisplay    *display);
 GDK_AVAILABLE_IN_ALL
 void     gdk_display_notify_startup_complete   (GdkDisplay    *display,
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index f5eb162942..da01a8c6ea 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -6522,6 +6522,9 @@ gdk_window_set_static_gravities (GdkWindow *window,
  * Returns: %TRUE if the window is composited.
  *
  * Since: 2.22
+ *
+ * Deprecated: 3.16: Compositing is an outdated technology that
+ *   only ever worked on X11.
  **/
 gboolean
 gdk_window_get_composited (GdkWindow *window)
@@ -6560,6 +6563,9 @@ gdk_window_get_composited (GdkWindow *window)
  * attempting to do so.
  *
  * Since: 2.12
+ *
+ * Deprecated: 3.16: Compositing is an outdated technology that
+ *   only ever worked on X11.
  */
 void
 gdk_window_set_composited (GdkWindow *window,
@@ -6582,12 +6588,14 @@ gdk_window_set_composited (GdkWindow *window,
 
   impl_class = GDK_WINDOW_IMPL_GET_CLASS (window->impl);
 
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
   if (composited && (!gdk_display_supports_composite (display) || !impl_class->set_composited))
     {
       g_warning ("gdk_window_set_composited called but "
                  "compositing is not supported");
       return;
     }
+G_GNUC_END_IGNORE_DEPRECATIONS
 
   impl_class->set_composited (window, composited);
 
diff --git a/gdk/gdkwindow.h b/gdk/gdkwindow.h
index 3617c55f3d..38a67b5afc 100644
--- a/gdk/gdkwindow.h
+++ b/gdk/gdkwindow.h
@@ -627,9 +627,9 @@ void gdk_window_shape_combine_region (GdkWindow	      *window,
 GDK_AVAILABLE_IN_ALL
 void gdk_window_set_child_shapes (GdkWindow *window);
 
-GDK_AVAILABLE_IN_ALL
+GDK_DEPRECATED_IN_3_16
 gboolean gdk_window_get_composited (GdkWindow *window);
-GDK_AVAILABLE_IN_ALL
+GDK_DEPRECATED_IN_3_16
 void gdk_window_set_composited   (GdkWindow *window,
                                   gboolean   composited);