PHP pspell_check returns always FALSE

Question

I want to use pspell_check to determine the complexity of passwords chosen by users. The problem is that my code, inspired by the basic examples available on the web, always returns FALSE. Example code:

$pspell_link = pspell_new('en');
echo (int)pspell_check($pspell_link, 'correct');
echo (int)pspell_check($pspell_link, 'wrongsishly');

What might be wrong in my setting?