Phone number regex string incorrect for italian phones

Hello,
I have an issue with italian phone numbers: this module allows only numbers with max 7 digits after the '/', but unfortunately in italy many numbers have 8 digits after /.

So, I changed the code of phone.it.inc as follows:
function valid_it_phone_number($phonenumber) {
// define regular expression
$regex = "/^(\+39)?[ ]?([0-9]{2,3}(\/|-| )?[0-9]{6,8})$/i";

// return true if valid, false otherwise
return (bool) preg_match($regex, $phonenumber);
}

I hope I did everything nice.