Index: Lib/tkinter/filedialog.py
===================================================================
--- Lib/tkinter/filedialog.py	(revision 67276)
+++ Lib/tkinter/filedialog.py	(working copy)
@@ -350,7 +350,7 @@
 
 
 # the directory dialog has its own _fix routines.
-class Directory(Dialog):
+class Directory(commondialog.Dialog):
     "Ask for a directory"
 
     command = "tk_chooseDirectory"