Doctrine embedded value objects with single table inheritance

Content.php

<?php

namespace ContentBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use DateTime;
use DateTimeZone;

/**
 * @ORM\Entity
 * @ORM\Table(name="content")
 * @ORM\InheritanceType("SINGLE_TABLE")
 * @ORM\DiscriminatorColumn(name="type", type="string")
 * @ORM\DiscriminatorMap({
 *      "default"="Content",
 *      "page"="PageContent",
 *      "post"="PostContent"
 * })
 */
class Content
{
    /**
     * @var integer
     *
     * @ORM\Column(type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @var Guid
     *
     * @ORM\Embedded(class="Guid")
     */
    private $guid;

    /**
     * @var string
     *
     * @ORM\Column(type="text")
     */
    private $title;

    /**
     * @var string
     *
     * @ORM\Column(type="text")
     */
    private $body;

    /**
     * @var PublishStatus
     *
     * @ORM\Embedded(class="PublishStatus")
     */
    private $status;

    /**
     * @var \DateTime
     *
     * @ORM\Column(type="datetime")
     */
    private $created;

    /**
     * @var \DateTime
     *
     * @ORM\Column(type="datetime")
     */
    private $modified;

    /**
     * @var \DateTime
     *
     * @ORM\Column(type="datetime")
     */
    private $published;

    /**
     * @var \DateTime
     *
     * @ORM\Column(type="datetime")
     */
    private $embargoed;

    /**
     * @var \DateTime
     *
     * @ORM\Column(type="datetime")
     */
    private $expires;

    public function __construct(
        $title,
        $body
    ) {
        $this->title = $title;
        $this->body = $body;
        $this->status = PublishStatus::draft();
        $this->created = new DateTime('now', new DateTimeZone('UTC'));
    }

    public function publish(DateTime $published = null)
    {
        if (!$published) {
            $published = new DateTime('now', new DateTimeZone('UTC'));
        }

        $this->status = PublishStatus::usable();
        $this->published = clone $published;
    }

    public function withGuid(Guid $guid)
    {
        $this->guid = $guid;
    }

    public function withEmbargo(DateTime $embargoed = null)
    {
        $this->embargoed = clone $embargoed;
    }

    public function withExpiration(DateTime $expires = null)
    {
        $this->expires = clone $expires;
    }
}

Guid.php

<?php

namespace ContentBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Embeddable
 */
class Guid
{
    /**
     * @ORM\Column(type="string", nullable=true)
     */
    protected $value;

    public function __construct($value)
    {
        $this->value = \strval($value);
    }

    /**
     * @return string
     */
    public function __toString()
    {
        return $this->value;
    }
}

PageContent.php

<?php

namespace ContentBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 */
class PageContent extends Content
{
    public function __construct(
        $title,
        $body
    ) {
        parent::__construct($title, $body);
    }
}

PostContent.php

<?php

namespace ContentBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Entity
 */
class PostContent extends Content
{
    /**
     * @var string
     *
     * @ORM\Column(type="text")
     */
    private $excerpt;

    public function __construct(
        $title,
        $body,
        $excerpt = null
    ) {
        parent::__construct($title, $body);

        $this->excerpt = $excerpt;
    }
}

PublishStatus.php

<?php

namespace ContentBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * @ORM\Embeddable
 */
class PublishStatus
{
    const STATE_DRAFT = 'draft';
    const STATE_USABLE = 'usable';
    const STATE_WITHHELD = 'withheld';
    const STATE_CANCELED = 'canceled';

    /**
     * @ORM\Column(type="string")
     */
    private $status;

    /**
     * @param string $status
     * @throws \Exception
     */
    public function __construct($status)
    {
        if (!in_array($status, [self::STATE_DRAFT, self::STATE_USABLE, self::STATE_WITHHELD, self::STATE_CANCELED])) {
            throw new \Exception(sprintf('Invalid status: %s', $status));
        }

        $this->status = $status;
    }

    public static function draft()
    {
        return new self(self::STATE_DRAFT);
    }

    public static function usable()
    {
        return new self(self::STATE_USABLE);
    }

    public static function withheld()
    {
        return new self(self::STATE_WITHHELD);
    }

    public static function canceled()
    {
        return new self(self::STATE_CANCELED);
    }

    public function equals(PublishStatus $status)
    {
        return ($this->status == (string) $status);
    }

    /**
     * @return string
     */
    public function __toString()
    {
        return $this->status;
    }
}

When updating the schema I get this:

> php app/console doctrine:schema:update --force

[ReflectionException]
Property ContentBundle\Entity\PageContent::$guid does not exist

Without the single table inheritance it works perfectly and it creates the correct table structure.