diff --git a/clutter/clutter/x11/clutter-stage-x11.c b/clutter/clutter/x11/clutter-stage-x11.c
index d19241e3d..b2313f31a 100644
--- a/clutter/clutter/x11/clutter-stage-x11.c
+++ b/clutter/clutter/x11/clutter-stage-x11.c
@@ -432,7 +432,7 @@ clutter_stage_x11_unrealize (ClutterStageWindow *stage_window)
   clutter_stage_window_parent_iface->unrealize (stage_window);
 }
 
-void
+static void
 _clutter_stage_x11_update_foreign_event_mask (CoglOnscreen *onscreen,
                                               guint32 event_mask,
                                               void *user_data)
diff --git a/clutter/clutter/x11/clutter-stage-x11.h b/clutter/clutter/x11/clutter-stage-x11.h
index a359c991a..315939e95 100644
--- a/clutter/clutter/x11/clutter-stage-x11.h
+++ b/clutter/clutter/x11/clutter-stage-x11.h
@@ -91,9 +91,6 @@ struct _ClutterStageX11Class
 
 GType _clutter_stage_x11_get_type (void) G_GNUC_CONST;
 
-void  _clutter_stage_x11_update_foreign_event_mask (CoglOnscreen *onscreen,
-                                                    guint32 event_mask,
-                                                    void *user_data);
 void  _clutter_stage_x11_events_device_changed (ClutterStageX11 *stage_x11,
                                                 ClutterInputDevice *device,
                                                 ClutterDeviceManager *device_manager);