diff --git a/ChatTwo/Message.cs b/ChatTwo/Message.cs
index 3615738..54db588 100755
--- a/ChatTwo/Message.cs
+++ b/ChatTwo/Message.cs
@@ -54,7 +54,7 @@ internal class Message {
         }
     }
 
-    internal Message(ObjectId id, ulong receiver, ulong contentId, DateTime date, BsonDocument code, BsonArray sender, BsonArray content, BsonDocument senderSource, BsonDocument contentSource, BsonDocument sortCode) {
+    internal Message(ObjectId id, ulong receiver, ulong contentId, DateTime date, BsonDocument code, BsonArray sender, BsonArray content, BsonValue senderSource, BsonValue contentSource, BsonDocument sortCode) {
         this.Id = id;
         this.Receiver = receiver;
         this.ContentId = contentId;
@@ -62,8 +62,8 @@ internal class Message {
         this.Code = BsonMapper.Global.ToObject<ChatCode>(code);
         this.Sender = BsonMapper.Global.Deserialize<List<Chunk>>(sender);
         this.Content = BsonMapper.Global.Deserialize<List<Chunk>>(content);
-        this.SenderSource = BsonMapper.Global.ToObject<SeString>(senderSource);
-        this.ContentSource = BsonMapper.Global.ToObject<SeString>(contentSource);
+        this.SenderSource = BsonMapper.Global.Deserialize<SeString>(senderSource);
+        this.ContentSource = BsonMapper.Global.Deserialize<SeString>(contentSource);
         this.SortCode = BsonMapper.Global.ToObject<SortCode>(sortCode);
 
         foreach (var chunk in this.Sender.Concat(this.Content)) {
diff --git a/ChatTwo/Store.cs b/ChatTwo/Store.cs
index 96c9985..dc04067 100755
--- a/ChatTwo/Store.cs
+++ b/ChatTwo/Store.cs
@@ -52,8 +52,8 @@ internal class Store : IDisposable {
                 doc["Code"].AsDocument,
                 doc["Sender"].AsArray,
                 doc["Content"].AsArray,
-                doc["SenderSource"].AsDocument,
-                doc["ContentSource"].AsDocument,
+                doc["SenderSource"],
+                doc["ContentSource"],
                 doc["SortCode"].AsDocument
             ));
         BsonMapper.Global.RegisterType<Payload?>(
@@ -88,6 +88,22 @@ internal class Store : IDisposable {
 
                 return Payload.Decode(new BinaryReader(new MemoryStream(bson.AsBinary)));
             });
+        BsonMapper.Global.RegisterType<SeString?>(
+            seString => seString == null
+                ? null
+                : new BsonArray(seString.Payloads.Select(payload => new BsonValue(payload.Encode()))),
+            bson => {
+                if (bson.IsNull) {
+                    return null;
+                }
+
+                var array = bson.IsArray ? bson.AsArray : bson["Payloads"].AsArray;
+                var payloads = array
+                    .Select(payload => Payload.Decode(new BinaryReader(new MemoryStream(payload.AsBinary))))
+                    .ToList();
+                return new SeString(payloads);
+            }
+        );
         BsonMapper.Global.RegisterType(
             type => (int) type,
             bson => (ChatType) bson.AsInt32