diff --git a/Lib/argparse.py b/Lib/argparse.py
index 94e1b8ad0ed..c529e8ad361 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -746,7 +746,7 @@ class ArgumentError(Exception):
         if self.argument_name is None:
             format = '%(message)s'
         else:
-            format = 'argument %(argument_name)s: %(message)s'
+            format = _('argument %(argument_name)s: %(message)s')
         return format % dict(message=self.message,
                              argument_name=self.argument_name)