diff --git a/akka-durable-mailboxes/akka-mongo-mailbox/src/main/scala/akka/actor/mailbox/BSONSerialization.scala b/akka-durable-mailboxes/akka-mongo-mailbox/src/main/scala/akka/actor/mailbox/BSONSerialization.scala
index 5aa314eb55..8da4db9376 100644
--- a/akka-durable-mailboxes/akka-mongo-mailbox/src/main/scala/akka/actor/mailbox/BSONSerialization.scala
+++ b/akka-durable-mailboxes/akka-mongo-mailbox/src/main/scala/akka/actor/mailbox/BSONSerialization.scala
@@ -26,7 +26,7 @@ class BSONSerializableMailbox(system: ExtendedActorSystem) extends SerializableB
     val b = Map.newBuilder[String, Any]
     b += "_id" -> msg._id
     b += "ownerPath" -> msg.ownerPath
-    b += "senderPath" -> msg.sender.path
+    b += "senderPath" -> msg.sender.path.toString
 
     /**
      * TODO - Figure out a way for custom serialization of the message instance