Class 'App\Http\Controllers\Session' not found Laravel 5.2

Hi guys i'm using sessions in Laravel 5.2 there is my Controller code :

if (Session::has('panier'))
        {
            $panier = Session::get('panier');  
        }

i try just to get a value from the session , and i got this error :

FatalErrorException in ProduitsController.php line 106: Class 'App\Http\Controllers\Session' not found

How can i resolve it ?

via Chebli Mohamed