Symfony 2 / Doctrine 2: Two Entities for the same table, use one in favour of the other

In my Symfony2 application I extracted most of my Entities into a separate library which I install using composer. This library does not have a dependency on Symfony2 (but does depend on Doctrine because I use annotations), because I would like to use it in other non-Symfony2 projects as well. The library contains a `ClientUser` Entity, which maps to a `client_users` table. In my Symfony2 application, I would like to use the same `ClientUser` Entity for authentication. This requires me to implement `Symfony\Component\Security\Core\User\UserInterface`. The problem is that I would like to have both a 'Symfony2-agnostic' and a 'Symfony-aware' implementation of a `ClientUser` Entity (which both should map to the same table). I tried to extend both classes from a ClientUserAbstract Entity, but it didn't work. ``` <?php namespace My\Library\Entity; use Doctrine\ORM\Mapping as ORM; /** * @ORM\MappedSuperClass */ class ClientUserAbstract { // all my fields here } ``` My "Symfony2-agnostic" Entity: ``` <?php namespace My\Library\Entity; use Doctrine\ORM\Mapping as ORM; /** * @ORM\Entity */ class ClientUser extends ClientUserAbstract { // nothing here, it's empty } ``` My "Symfony2-aware" Entity: ``` <?php namespace Vendor\Bundle\MyBundle\Entity; use Doctrine\ORM\Mapping as ORM; use Symfony\Component\Security\Core\User\UserInterface; /** * @ORM\Entity */ class ClientUser extends ClientUserAbstract implements UserInterface { // all methods that Symfony requires because of the UserInterface here: public function getRoles(); public function getPassword(); public function getSalt(); public function getUsername(); public function eraseCredentials(); } ``` My Symfony 2 app now detects two Entities which point to the same table and fails with an Exception. I either need to tell my Symfony2 app to "ignore" my `My\Library\Entity\ClientUser`, or I need a way to extend it. Any ideas?