PHP 5.3 compatibility

I use PHP 5.3 and get errors on form submit -

* warning: Parameter 2 to hierarchical_select_form_alter() expected to be a reference, value given in /home/sitedir/includes/common.inc on line 2883.

I found that error is in PHP 5.3 incompatibility. On other site with 5.2 all works fine.

/**
 * Implementation of hook_form_alter().
 */
function hierarchical_select_form_alter(&$form, &$form_state, $form_id) {
  if (_hierarchical_select_form_has_hierarchical_select($form)) {
    $form['#after_build'][] = 'hierarchical_select_after_build';
  }
}

So, I found that to solve this errors the module needs to be pathed like this:

- function hierarchical_select_form_alter(&$form, &$form_state, $form_id) {
+ function hierarchical_select_form_alter($form, $form_state, $form_id) {

am I right?