diff --git a/Lib/argparse.py b/Lib/argparse.py
index 8d1a00ad2207e5..1c5520c4b41bd1 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -766,7 +766,7 @@ def __str__(self):
         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)