Index: Lib/test/test_urllibnet.py
===================================================================
--- Lib/test/test_urllibnet.py	(revision 81877)
+++ Lib/test/test_urllibnet.py	(working copy)
@@ -181,6 +181,7 @@
         self.assertIsInstance(header, email.message.Message,
                               "header is not an instance of email.message.Message")
 
+    @support.run_with_locale('LC_TIME', 'C')
     def test_data_header(self):
         logo = "http://www.python.org/community/logos/python-logo-master-v3-TM.png"
         file_location, fileheaders = self.urlretrieve(logo)
@@ -190,7 +191,7 @@
         try:
             time.strptime(datevalue, dateformat)
         except ValueError:
-            self.fail('Date value not in %r format', dateformat)
+            self.fail('Date value not in %r format' %  dateformat)
 
 
 def test_main():