diff --git a/Lib/lib-tk/tkCommonDialog.py b/Lib/lib-tk/tkCommonDialog.py
index c63ca11..55cf064 100644
--- a/Lib/lib-tk/tkCommonDialog.py
+++ b/Lib/lib-tk/tkCommonDialog.py
@@ -27,6 +27,8 @@
 
         self.master  = master
         self.options = options
+        if not master and options.get('parent'):
+            self.master = options['parent']
 
     def _fixoptions(self):
         pass # hook