Warden used to switch back to the default locale on throw and it's already fixed by passing the current locale to Warden as an option. There are two hooks - Activatable and Timeoutable - that also rely on throw :warden. In these instances, however, the locale is not currently passed down to Warden so even if the corresponding error messages (this and this) are translated to other languages, they are always displayed with the default locale.

The fix is simple: where throw is used (here and here), it should be called with locale: options[:locale].