class Test(x: => Object) extends Serializable {
  @transient lazy val foo = x
}

object Foo {
  def main(args: Array[String]): Unit = {
    val t = new Test("foo")
    println(t.foo)
    val baos = new ByteArrayOutputStream
    val dos = new ObjectOutputStream(baos)
    dos.writeObject(t)
    dos.close()
    val dis = new ObjectInputStream(new ByteArrayInputStream(baos.toByteArray()))
    val t1 = dis.readObject().asInstanceOf[Test]
    println(t1.foo)
  }
}

foo
Exception in thread "main" java.lang.NullPointerException
	at test.Test.foo$lzycompute(Foo.scala:33)
	at test.Test.foo(Foo.scala:33)
	at test.Foo$.main(Foo.scala:46)
	at test.Foo.main(Foo.scala)