diff --git a/django/contrib/admin/sites.py b/django/contrib/admin/sites.py
index a3eb5143e7..9146b59537 100644
--- a/django/contrib/admin/sites.py
+++ b/django/contrib/admin/sites.py
@@ -231,7 +231,7 @@ class AdminSite(object):
                 else:
                     if user.check_password(password):
                         message = _("Your e-mail address is not your username."
-                                    " Try '%s' instead." % user.username) 
+                                    " Try '%s' instead.") % user.username
                     else:
                         message = _("Usernames cannot contain the '@' character.")
             return self.display_login_form(request, message)