diff --git a/Lib/getopt.py b/Lib/getopt.py
index 4285cbb284b..04e881ec73d 100644
--- a/Lib/getopt.py
+++ b/Lib/getopt.py
@@ -39,7 +39,7 @@ import os
 class GetoptError(Exception):
     opt = ''
     msg = ''
-    def __init__(self, msg, opt):
+    def __init__(self, msg, opt=''):
         self.msg = msg
         self.opt = opt
         Exception.__init__(self, msg, opt)