diff --git a/wxPython/demo/Threads.py b/wxPython/demo/Threads.py
index ceb2fdc78b..96ef2afd42 100644
--- a/wxPython/demo/Threads.py
+++ b/wxPython/demo/Threads.py
@@ -211,10 +211,13 @@ class TestPanel(wx.Panel):
 
 
     def OnButton(self, evt):
-        win = TestFrame(self, self.log)
-        win.Show(True)
+        self.win = TestFrame(self, self.log)
+        self.win.Show(True)
 
 
+    def ShutdownDemo(self):
+        self.win.Close()
+
 #---------------------------------------------------------------------------