def validate_unique(self, exclude=None):
        """
        Also validate the unique_together of the translated model.
        """
        # This is called from ModelForm._post_clean() or Model.full_clean()
        errors = {}
        try:
            super(TranslatableModelMixin, self).validate_unique(exclude=exclude)
        except ValidationError as e:
            errors = e.message_dict

        for local_cache in six.itervalues(self._translations_cache):
            for translation in six.itervalues(local_cache):
                if is_missing(translation):  # Skip fallback markers
                    continue

                try:
                    translation.validate_unique(exclude=exclude)
                except ValidationError as e:
                    errors.update(e.message_dict)

        if errors:
            raise ValidationError(errors)
Also validate the unique_together of the translated model.