Akka remote actors, superclass without default constructor

I am trying to send a message using akka remote actors, where the case class is a subclass of a superclass taking argument in its constructor.

Here is a minimum example to reproduce the problem:

package com.tuvistavie.testremote

import akka.actor.{ Actor, ActorSystem, Props, ActorLogging }
import com.typesafe.config.ConfigFactory

abstract class Foo(val a: Int)
case class MessageFoo(override val a: Int) extends Foo(a)

object Sender {
  def main(args: Array[String]) {
    val system = ActorSystem("Sender", ConfigFactory.load.getConfig("sender"))
    val actor = system.actorFor("akka://Receiver@127.0.0.1:2552/user/receiver")
    actor ! MessageFoo(1)
  }
}

object Receiver {
  class ReceiverActor extends Actor with ActorLogging {
    def receive = {
      case m: MessageFoo => log.debug(m.toString)
    }
  }

  def main(args: Array[String]) {
    val system = ActorSystem("Receiver", ConfigFactory.load.getConfig("receiver"))
    val actor = system.actorOf(Props[ReceiverActor], "receiver")
  }
}

When running this code, I get the following error:

[ERROR] [06/26/2013 02:53:16.132] [Receiver-9] 
[NettyRemoteTransport(akka://Receiver@127.0.0.1:2552)] 
RemoteServerError@akka://Receiver@127.0.0.1:2552] Error[java.io.InvalidClassException: com.tuvistavie.testremote.MessageFoo; no valid constructor]

I think it is because the message cannot be deserialized (using akka.serialization.JavaSerializer), because of the parents' constructor. If it were only one or two messages I know I could write my own serializer, but I have plenty of case classes like this in my application.

Would there be any easy way to pass this kind of object using remote actors?

Things will work if you restructure like so:

trait Foo{
  val a:Int
}
case class MessageFoo(a:Int) extends Foo

I generally try and stay away from class inheritance with case classes. If I need to be able to refer to a set of case classes as an abstract type, I use traits instead.