diff --git a/ChangeLog b/ChangeLog
index 6e9d218d4..682098890 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2009-06-09  Matthias Clasen  <mclasen@redhat.com>
+
+	unset _NET_SUPPORTING_WM_CHECK when shutting down
+
 2009-06-08  Tomeu Vizoso  <tomeu@sugarlabs.org>
 
 	Add a switch to disable autofullscreen'ing maximized windows without decorations
diff --git a/src/core/screen.c b/src/core/screen.c
index e82dd932e..e2e3f5680 100644
--- a/src/core/screen.c
+++ b/src/core/screen.c
@@ -86,6 +86,13 @@ set_wm_check_hint (MetaScreen *screen)
   return Success;
 }
 
+static void
+unset_wm_check_hint (MetaScreen *screen)
+{
+  XDeleteProperty (screen->display->xdisplay, screen->xroot, 
+                   screen->display->atom__NET_SUPPORTING_WM_CHECK);
+}
+
 static int
 set_supported_hint (MetaScreen *screen)
 {
@@ -661,6 +668,8 @@ meta_screen_free (MetaScreen *screen,
     meta_warning (_("Could not release screen %d on display \"%s\"\n"),
                   screen->number, screen->display->name);
 
+  unset_wm_check_hint (screen);
+
   XDestroyWindow (screen->display->xdisplay,
                   screen->wm_sn_selection_window);