diff --git a/Lib/idlelib/ScriptBinding.py b/Lib/idlelib/ScriptBinding.py
index 0140c69..dcb5f9a 100644
--- a/Lib/idlelib/ScriptBinding.py
+++ b/Lib/idlelib/ScriptBinding.py
@@ -155,6 +155,7 @@
                                 message=msg,
                                 icon=tkMessageBox.QUESTION,
                                 type=tkMessageBox.OKCANCEL,
+                                default=tkMessageBox.OK,
                                 master=self.editwin.text)
             reply = mb.show()
             if reply == "ok":