mb_ereg_replace has allegedly been removed

[Stadly]

mb_ereg_replace(' ', '-', $str);

PhpDeprecationDetector outputs:

Function mb_ereg_replace() is removed.
Consider replace with @mb_ereg_replace_e_modifier()

I can't find any evidence that mb_ereg_replace has been removed, nor any reference to what mb_ereg_replace_e_modifier is.