How to use non-latin characters in slug?

The posts table contains a record where slug field is: пролпрол-про-апрарр

I try to get the post using controller:

public function view($slug = NULL){


    $data['post'] = $this->post_model->get_posts($slug);

    if(empty($data['post'])){
        show_404();
    }
    ...

A link to view this post in browser

http://localhost/ciblog/posts/пролпрол-про-апрарр

but note, when I copied it to paste it here it is:

http://localhost/ciblog/posts/%D0%BF%D1%...1%80%D1%80

For some reason in browser I get

404 Page Not Found

How can I fix that to use a non-latin slug?

I have changed permitted_uri_chars to be

Code:

[size=small][i]a-z 0-9~%.:_-абвгдеёжзийклмнопрстуфхцчшщъыьэюя[/i][/size]

but it seems nothing changed.