Slim 3 with Doctrine 2

I tried to configure Slim 3 with Doctrine 2 following this guide, but when I try to find the entities i got the following error: "Class "Entity\User" is not a valid entity or mapped super class.".

My entity looks good. Where is the problem?

<?php

namespace Entity;

use Entity;
use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 * @ORM\Table(name="users")
 */
class User {

    // <editor-fold desc="Fields">

    /**
     * @ORM\Id
     * @ORM\Column(name="user_id", type="integer")
     * @ORM\GeneratedValue
     */
    protected $id;

    // </editor-fold>

}

make these changes on your first 2 lines

namespace App\Entity;
use App\Entity;

This should work