PHP 4.1 crypt()

Is there any way to force PHP 4.1's crypt to generate crypt's with 2-letter salts? We've written some apps that do things the hack way -- if (crypt($pass,substr($pass,0,2)) == $cryptpass) -- and changing all of them to work the extended way is a real pain the arse. That includes changing all our password generation code to create 2-letter salts. Any help much appreciated. In short -- I want crypt() to work like it did in 4.0.6. Mike