PHP syntax error on module install

Get this error when enabling the module:

Parse error: syntax error, unexpected '=', expecting ')' in /usr/local/apache/htdocs/sites/theflavasumtrust.org/modules/filefield/filefield.module on line 216

The problem is this function definition:

function filefield_field($op, &$node, $field, &$items = array()) {

The site uses PHP 4.4.8, which may be why I've not had this problem before.