Using Codeception acceptance tests with symfony 2

I want to use Codeception to write some acceptance tests in symfony 2 project. I don't want to use PhpBrowser but symfony envoriment.

Original acceptance.suite.yml

class_name: AcceptanceTester
modules:
    enabled:
        - PhpBrowser:
            url: http://localhost/myapp
        - \Helper\Acceptance

I change it to:

class_name: AcceptanceTester
modules:
    enabled: Symfony2
    config:
        Symfony2:
            app_path:   'app'
            environment:    'test'

But now i can't use \Helper\Acceptance to write my tests using codeception

$I = new AcceptanceTester($scenario);
$I->wantTo('choose my store');
$I->amOnPage('/');
$I->amGoingTo('/welcome');

How to set up config to run tests on app, instead via PhpBrowser?