PHP Fatal error: Cannot use object of type stdClass

Происходит ошибка:

PHP Fatal error:  Cannot use object of type stdClass as array in /home/p21522/public_html/vk2/src/Vkontakte.php on line 417

417 строка скрипта:

'attachments' => "{$response[0]->id}", // uploaded image is passed as attachment

Как исправить?