How to modify mb_convert_case function for a locale language exception?

Question

I convert titles to MB_CASE_TITLE case with:

$title_of_post_case = mb_convert_case($title_of_post, MB_CASE_TITLE);

However, there is an exception in our locale language: Lowercase of I letter is ı (not i). So, KALDIRIMLAR word converts to Kaldirimlar instead of Kaldırımlar.

How can I solve this problem?