django blocktrans and i18n in templates

Question

I have an i18n problem in django:

This works fine :

{% trans cat.name %}  

cat.name will be translated

But t

Answer 1

{% blocktrans with cat.name as cat_slug %}{{ cat_slug|capfirst }}{% endblocktrans %}

?

EDIT: you were right the doc says the filter as to be placed in the blocktrans