Abstract class marked as @Entity in a single table inheritance is wrongly hydrated

I have the following entity hierarchy:

/**
 * @Entity
 * @InheritanceType("SINGLE_TABLE")
 * @DiscriminatorColumn(name="type", type="string")
 * @DiscriminatorMap({
     "prospectEdited" = "Application\Domain\Model\Event\ProspectEditedEvent"
   })
 */
abstract class Event {
	// ...
}

/**
 * @Entity
 */
abstract class ProspectEvent extends Event {
    /**
     * @ManyToOne(targetEntity="Application\Domain\Model\Prospect")
     */
    protected $prospect;
}

/**
 * @Entity
 */
class ProspectEditedEvent extends ProspectEvent {
	// ...
}

Although ProspectEvent is an abstract class, I need to mark it as @Entity, so that I can query for any type of ProspectEvent:

SELECT e FROM ProspectEvent e WHERE e.prospect = ?

So far, so good.
The problem happens when I query the root class:

SELECT e FROM Event e

The query works fine, but the returned ProspectEvent entities have a NULL $prospect property.
I noticed that in that case, the DocBlock for $prospect is totally ignored (a wrong @JoinColumn name for example, doesn't throw an exception).

The workaround to make it work, is to add a "fake" entry to the discriminator map for the abstract class:

@DiscriminatorMap({
  "prospectEvent"  = "Application\Domain\Model\Event\ProspectEvent"
  "prospectEdited" = "Application\Domain\Model\Event\ProspectEditedEvent"
})

Even though there is no such "prospectEvent" discriminator entry possible, as the class is abstract.
Final point, if I remove the @Entity DocBlock on ProspectEvent, $prospect is hydrated correctly, but then it is not possible to issue a DQL query on ProspectEvent anymore.