Arabian language doesn't work in angular-gettext?

Question

I prepared ar.po file with translations, compile it into translations.js (along with other languages), but when I try setCurrentLanguage("ar"); it doesn't appears, I see default string constants instead. However, other languages work perfect, for example setCurrentLanguage("fr");

Edit:

I also can see "[MISSING]" near every string when gettextCatalog.debug = true;. Seems like angular-gettext doesn't see arabian strings, however it exists in translations.js.

Is there some workaround?