diff --git a/moffy-samples-gtk3-run.cabal b/moffy-samples-gtk3-run.cabal
--- a/moffy-samples-gtk3-run.cabal
+++ b/moffy-samples-gtk3-run.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           moffy-samples-gtk3-run
-version:        0.1.0.4
+version:        0.1.0.6
 synopsis:       Package to run moffy samples - GTK3 version
 description:    Please see the README on GitHub at <https://github.com/YoshikuniJujo/moffy-samples-gtk3-run#readme>
 category:       Control
@@ -34,6 +34,7 @@
       Stopgap.Graphics.UI.Gdk.Event
       Stopgap.Graphics.UI.Gdk.Event.Button
       Stopgap.Graphics.UI.Gdk.Event.Motion
+      Stopgap.Graphics.UI.Gdk.Window
       Stopgap.Graphics.UI.Gtk
       Stopgap.Graphics.UI.Gtk.Container
       Stopgap.Graphics.UI.Gtk.DrawingArea
diff --git a/src/Control/Moffy/Samples/Run/Gtk3.hs b/src/Control/Moffy/Samples/Run/Gtk3.hs
--- a/src/Control/Moffy/Samples/Run/Gtk3.hs
+++ b/src/Control/Moffy/Samples/Run/Gtk3.hs
@@ -48,6 +48,7 @@
 import Stopgap.Graphics.UI.Gdk.Event qualified as Gdk.Event
 import Stopgap.Graphics.UI.Gdk.Event.Button qualified as Gdk.Event.Button
 import Stopgap.Graphics.UI.Gdk.Event.Motion qualified as Gdk.Event.Motion
+import Stopgap.Graphics.UI.Gdk.Window qualified as Gdk.Window
 
 type Events = CalcTextExtents :-
 	Mouse.Move :- Mouse.Down :- Mouse.Up :- Singleton DeleteEvent
@@ -89,6 +90,9 @@
 movePoint :: Gdk.Event.Motion.M -> Point
 movePoint em = (Gdk.Event.Motion.mX em, Gdk.Event.Motion.mY em)
 
+deleteHandle :: a -> b -> IO Bool
+deleteHandle x y = pure False
+
 runSingleWin ::
 	TChan (EvReqs Events) -> TChan (EvOccs Events) -> TChan View -> IO ()
 runSingleWin cer ceo cv = do
@@ -98,6 +102,7 @@
 	join $ Gtk.init <$> getProgName <*> getArgs
 
 	w <- Gtk.Window.new Gtk.Window.Toplevel
+	G.Signal.connect_ab_bool w "delete-event" deleteHandle Null
 	G.Signal.connect_void_void w "destroy" Gtk.mainQuit Null
 
 	da <- Gtk.DrawingArea.new
@@ -128,7 +133,11 @@
 
 	forkIO . forever $ atomically (readTChan cv) >>= \case
 		Stopped -> void $ G.idleAdd
-			(\_ -> Gtk.Window.close w >> Gtk.mainQuit >> pure False)
+			(\_ -> do
+				Gtk.Window.close w
+				Gdk.Window.destroy =<< Gtk.Widget.getWindow w
+				Gtk.mainQuit
+				pure False)
 			Null
 		View v -> do
 			atomically $ writeTVar crd v
diff --git a/src/Stopgap/Graphics/UI/Gdk/Window.hsc b/src/Stopgap/Graphics/UI/Gdk/Window.hsc
new file mode 100644
--- /dev/null
+++ b/src/Stopgap/Graphics/UI/Gdk/Window.hsc
@@ -0,0 +1,14 @@
+{-# OPTIONS_GHC -Wall -fno-warn-tabs #-}
+
+module Stopgap.Graphics.UI.Gdk.Window where
+
+import Foreign.Ptr
+
+data WTag
+
+newtype W = W (Ptr WTag) deriving Show
+
+destroy :: W -> IO ()
+destroy = c_gdk_window_destroy
+
+foreign import ccall "gdk_window_destroy" c_gdk_window_destroy :: W -> IO ()
diff --git a/src/Stopgap/Graphics/UI/Gtk/Widget.hsc b/src/Stopgap/Graphics/UI/Gtk/Widget.hsc
--- a/src/Stopgap/Graphics/UI/Gtk/Widget.hsc
+++ b/src/Stopgap/Graphics/UI/Gtk/Widget.hsc
@@ -6,6 +6,7 @@
 import Foreign.Ptr
 import Stopgap.System.GLib.Object qualified as G.Object
 import Stopgap.Graphics.UI.Gdk.Event qualified as Gdk.Event
+import Stopgap.Graphics.UI.Gdk.Window qualified as Gdk.Window
 
 class G.Object.IsO w => IsW w where toW :: w -> W
 
@@ -24,8 +25,14 @@
 foreign import ccall "gtk_widget_add_events" c_gtk_widget_add_events ::
 	W -> Gdk.Event.Mask -> IO ()
 
-queueDraw :: IsW w => w ->IO ()
+queueDraw :: IsW w => w -> IO ()
 queueDraw = c_gtk_widget_queue_draw . toW
 
 foreign import ccall "gtk_widget_queue_draw" c_gtk_widget_queue_draw ::
 	W -> IO ()
+
+getWindow :: IsW w => w -> IO Gdk.Window.W
+getWindow = c_gtk_widget_get_window . toW
+
+foreign import ccall "gtk_widget_get_window" c_gtk_widget_get_window ::
+	W -> IO Gdk.Window.W
diff --git a/src/Stopgap/Graphics/UI/Gtk/Window.hsc b/src/Stopgap/Graphics/UI/Gtk/Window.hsc
--- a/src/Stopgap/Graphics/UI/Gtk/Window.hsc
+++ b/src/Stopgap/Graphics/UI/Gtk/Window.hsc
@@ -13,6 +13,7 @@
 import Stopgap.System.GLib.Object qualified as G.Object
 import Stopgap.Graphics.UI.Gtk.Widget qualified as Widget
 import Stopgap.Graphics.UI.Gtk.Container qualified as Container
+import Stopgap.Graphics.UI.Gdk.Window qualified as Gdk.Window
 
 #include <gtk/gtk.h>