phpstan: Error without leading backslash?

Hello,
I have a problem with my classes. It seems that phpstan marks as errors the class names like these:

/**
 * Verifies the token and returns the associated user.
 *
 * @param string $accessToken
 *
 * @return AppBundle\Model\SocialUser
 */
public function verifyToken($idTokenString)
{
    //
}

  Line   src/AppBundle/Service/FacebookHelper.php                                                    
 ------ -------------------------------------------------------------------------------------------- 
  34     Return typehint of method AppBundle\Service\FacebookHelper::verifyToken() has invalid type  
         AppBundle\Service\AppBundle\Model\SocialUser.  

If I put a leading slash then the error is silenced. Should I change all the classes?

Thanks.