diff --git a/libs/gtkmm2ext/gtkapplication_quartz.mm b/libs/gtkmm2ext/gtkapplication_quartz.mm
index 38db6a2d42..f83180f4c9 100644
--- a/libs/gtkmm2ext/gtkapplication_quartz.mm
+++ b/libs/gtkmm2ext/gtkapplication_quartz.mm
@@ -59,7 +59,7 @@
 
 static gint _exiting = 0;
 static std::vector<GtkMenuItem*> global_menu_items;
-static bool _modal_state = false;
+static gint _modal_state = 0;
 
 static guint
 gdk_quartz_keyval_to_ns_keyval (guint keyval)
@@ -585,7 +585,7 @@ idle_call_activate (gpointer data)
 }
 - (BOOL) validateMenuItem:(NSMenuItem*) menuItem
 {
-	if (_modal_state) {
+	if (_modal_state > 0) {
 		return false;
 	}
 
@@ -1468,7 +1468,7 @@ namespace Gtk {
 - (NSApplicationTerminateReply) applicationShouldTerminate:(NSApplication *) app
 {
 	UNUSED_PARAMETER(app);
-	if (_modal_state) {
+	if (_modal_state > 0) {
 		return NSTerminateCancel;
 	}
 	Gtkmm2ext::Application::instance()->ShouldQuit ();
@@ -1480,14 +1480,18 @@ static void
 gdk_quartz_modal_notify (GdkWindow*, gboolean modal)
 {
 	/* this global will control sensitivity of our app menu items, via validateMenuItem */
-	_modal_state = modal;
+	if (modal) {
+		++_modal_state;
+	} else if (_modal_state > 0) {
+		--_modal_state;
+	}
 
 	/* Need to notify GTK that actions are insensitive where necessary */
 
 	for (auto & mitem : global_menu_items) {
 		GtkAction* act = gtk_activatable_get_related_action (GTK_ACTIVATABLE(mitem));
 		if (act) {
-			gtk_action_set_sensitive (act, !modal);
+			gtk_action_set_sensitive (act, 0 == _modal_state);
 		}
 	}
 }
diff --git a/libs/tk/ydk/quartz/gdkwindow-quartz.c b/libs/tk/ydk/quartz/gdkwindow-quartz.c
index 67d1077696..facb9b1e4b 100644
--- a/libs/tk/ydk/quartz/gdkwindow-quartz.c
+++ b/libs/tk/ydk/quartz/gdkwindow-quartz.c
@@ -197,7 +197,15 @@ gdk_window_impl_quartz_finalize (GObject *object)
 {
   GdkWindowImplQuartz *impl = GDK_WINDOW_IMPL_QUARTZ (object);
 
-  check_grab_destroy (GDK_DRAWABLE_IMPL_QUARTZ (object)->wrapper);
+  GdkWindow *window = GDK_DRAWABLE_IMPL_QUARTZ (object)->wrapper;
+  GdkWindowObject *private = (GdkWindowObject*) window;
+
+  check_grab_destroy (window);
+
+  if (private->modal_hint && _gdk_modal_notify)
+    {
+      _gdk_modal_notify (GDK_DRAWABLE_IMPL_QUARTZ (object)->wrapper, false);
+    }
 
   if (impl->paint_clip_region)
     gdk_region_destroy (impl->paint_clip_region);
@@ -2386,14 +2394,19 @@ void
 gdk_window_set_modal_hint (GdkWindow *window,
 			   gboolean   modal)
 {
+  GdkWindowObject *private;
+
   if (GDK_WINDOW_DESTROYED (window) ||
       !WINDOW_IS_TOPLEVEL (window))
     return;
 
-  if (_gdk_modal_notify) {
+  private = (GdkWindowObject*) window;
+
+  if (_gdk_modal_notify &&  private->modal_hint != modal) {
 	  _gdk_modal_notify (window, modal);
   }
-  /* FIXME: Implement */
+
+  private->modal_hint = modal;
 }
 
 void