'Set the GNUTranslations() fallback with the default language.'

def _add_fallback(self, localedirs=None):

    if ((self.__language == settings.LANGUAGE_CODE) or self.__language.startswith('en')):
        return
    if (self.domain == 'django'):
        default_translation = translation(settings.LANGUAGE_CODE)
    else:
        default_translation = DjangoTranslation(settings.LANGUAGE_CODE, domain=self.domain, localedirs=localedirs)
    self.add_fallback(default_translation)
