hook_regcode_validate not working

My workaround is to do something like this:

/**
 * Implements hook_form_FORM_ID_alter() to change the validation call back on regcode so that we can supplement it.
 */
function my_module_form_user_register_form_alter(&$form, &$form_state) {
  $form['regcode']['regcode_code']['#element_validate'] = array('my_module_element_validate');
}

/**
 * Validate the content of the code-field on user registration - call the regcode module validation, then add our own..
 */
function my_module_element_validate(&$element, &$form_state) {
  regcode_code_element_validate($element, $formstate);
  form_set_error('regcode_code', t('This just isn\'t working out between us.'));
}