diff --git a/gdk/quartz/gdkevents-quartz.c b/gdk/quartz/gdkevents-quartz.c
index 9e57edd..e8c28ad 100644
--- a/gdk/quartz/gdkevents-quartz.c
+++ b/gdk/quartz/gdkevents-quartz.c
@@ -46,6 +46,8 @@
 /* This is the window corresponding to the key window */
 static GdkWindow   *current_keyboard_window;

+static GdkWindow   *crossing_current_window = NULL;
+
 /* This is the event mask from the last event */
 static GdkEventMask current_event_mask;

@@ -1129,12 +1131,18 @@ synthesize_crossing_event (GdkWindow *window,
       if (!(private->event_mask & GDK_ENTER_NOTIFY_MASK))
         return FALSE;

+      if (crossing_current_window == window)
+        return FALSE;
+
       fill_crossing_event (window, event, nsevent,
                            x, y,
                            x_root, y_root,
                            GDK_ENTER_NOTIFY,
                            GDK_CROSSING_NORMAL,
                            GDK_NOTIFY_NONLINEAR);
+
+      crossing_current_window = window;
+
       return TRUE;

     case NSMouseExited:
@@ -1142,6 +1150,11 @@ synthesize_crossing_event (GdkWindow *window,
       if (!(private->event_mask & GDK_LEAVE_NOTIFY_MASK))
         return FALSE;

+      if (crossing_current_window != NULL && crossing_current_window != window)
+        return FALSE;
+
+      crossing_current_window = NULL;
+
       fill_crossing_event (window, event, nsevent,
                            x, y,
                            x_root, y_root,