Errors when using drush

WD php: Warning: Cannot modify header information - headers already sent by (output started at                                  [warning]
/home/foo/bin/drush/includes/drush.inc:579) in cookie_cache_bypass_adv_setcookie() (line 76 of
/home/foo/domains/dev.foo.bar.com/staging/sites/all/modules/contrib/cookie_cache_bypass_adv/cookie_cache_bypass_adv.module).

Just needs this in the hook_form_alter()

if (drupal_is_cli()) {
  return;
}