diff --git a/js/libtextsecure.js b/js/libtextsecure.js
index cac599ffe..017571e0b 100644
--- a/js/libtextsecure.js
+++ b/js/libtextsecure.js
@@ -37334,13 +37334,14 @@ MessageSender.prototype = {
         }.bind(this));
     },
 
-    sendSyncMessage: function(message, timestamp, destination) {
+    sendSyncMessage: function(encodedDataMessage, timestamp, destination) {
         var myNumber = textsecure.storage.user.getNumber();
         var myDevice = textsecure.storage.user.getDeviceId();
         if (myDevice != 1) {
+            var dataMessage = textsecure.protobuf.DataMessage.decode(encodedDataMessage);
             var sentMessage = new textsecure.protobuf.SyncMessage.Sent();
             sentMessage.timestamp = timestamp;
-            sentMessage.message = message;
+            sentMessage.message = dataMessage;
             if (destination) {
                 sentMessage.destination = destination;
             }
@@ -37348,7 +37349,6 @@ MessageSender.prototype = {
             syncMessage.sent = sentMessage;
             var contentMessage = new textsecure.protobuf.Content();
             contentMessage.syncMessage = syncMessage;
-
             return this.sendIndividualProto(myNumber, contentMessage, Date.now());
         }
     },
@@ -37393,12 +37393,13 @@ MessageSender.prototype = {
 
         return new Promise(function(resolve, reject) {
             this.sendMessageProto(timestamp, numbers, proto, function(res) {
+                res.dataMessage = proto.toArrayBuffer();
                 if (res.errors.length > 0)
                     reject(res);
                 else
                     resolve(res);
-            });
-        }.bind(this)).then(this.sendSyncMessage.bind(this, proto, timestamp));
+            }.bind(this));
+        }.bind(this));
     },
 
     sendMessageToNumber: function(number, messageText, attachments, timestamp) {
@@ -37407,8 +37408,12 @@ MessageSender.prototype = {
 
         return Promise.all(attachments.map(this.makeAttachmentPointer.bind(this))).then(function(attachmentsArray) {
             proto.attachments = attachmentsArray;
-            return this.sendIndividualProto(number, proto, timestamp).then(function() {
-                return this.sendSyncMessage(proto, timestamp, number);
+            return this.sendIndividualProto(number, proto, timestamp).then(function(res) {
+                res.dataMessage = proto.toArrayBuffer();
+                return res;
+            }.bind(this)).catch(function(res) {
+                res.dataMessage = proto.toArrayBuffer();
+                throw res;
             }.bind(this));
         }.bind(this));
     },
@@ -37573,6 +37578,7 @@ textsecure.MessageSender = function(url, username, password, attachment_server_u
     this.setGroupName                  = sender.setGroupName                 .bind(sender);
     this.setGroupAvatar                = sender.setGroupAvatar               .bind(sender);
     this.leaveGroup                    = sender.leaveGroup                   .bind(sender);
+    this.sendSyncMessage               = sender.sendSyncMessage              .bind(sender);
 };
 
 textsecure.MessageSender.prototype = {
diff --git a/js/models/conversations.js b/js/models/conversations.js
index ce684c724..0af25c16f 100644
--- a/js/models/conversations.js
+++ b/js/models/conversations.js
@@ -98,6 +98,9 @@
             sent_at        : now,
             received_at    : now
         });
+        if (this.isPrivate()) {
+            message.set({destination: this.id});
+        }
         message.save();
 
         this.save({
diff --git a/js/models/messages.js b/js/models/messages.js
index 5f4cb12ae..061ddfd37 100644
--- a/js/models/messages.js
+++ b/js/models/messages.js
@@ -140,13 +140,36 @@
 
         send: function(promise) {
             this.trigger('pending');
-            return promise.then(function() {
+            return promise.then(function(result) {
                 this.trigger('done');
+                if (result.dataMessage) {
+                    this.set({dataMessage: result.dataMessage});
+                }
                 this.save({sent: true});
-            }.bind(this)).catch(function(errors) {
+                this.sendSyncMessage();
+            }.bind(this)).catch(function(result) {
                 this.trigger('done');
+                if (result.dataMessage) {
+                    this.set({dataMessage: result.dataMessage});
+                }
                 this.set({sent: true});
                 this.saveErrors(result.errors);
+                if (result.successfulNumbers.length > 0) {
+                    this.sendSyncMessage();
+                }
+            }.bind(this));
+        },
+
+        sendSyncMessage: function() {
+            var dataMessage = this.get('dataMessage');
+            if (this.get('synced') || !dataMessage) {
+                return;
+            }
+
+            textsecure.messaging.sendSyncMessage(
+                dataMessage, this.get('sent_at'), this.get('destination')
+            ).then(function() {
+                this.save({synced: true, dataMessage: null});
             }.bind(this));
         },
 
diff --git a/libtextsecure/sendmessage.js b/libtextsecure/sendmessage.js
index 68ea349a7..f3dcb1bcb 100644
--- a/libtextsecure/sendmessage.js
+++ b/libtextsecure/sendmessage.js
@@ -66,13 +66,14 @@ MessageSender.prototype = {
         }.bind(this));
     },
 
-    sendSyncMessage: function(message, timestamp, destination) {
+    sendSyncMessage: function(encodedDataMessage, timestamp, destination) {
         var myNumber = textsecure.storage.user.getNumber();
         var myDevice = textsecure.storage.user.getDeviceId();
         if (myDevice != 1) {
+            var dataMessage = textsecure.protobuf.DataMessage.decode(encodedDataMessage);
             var sentMessage = new textsecure.protobuf.SyncMessage.Sent();
             sentMessage.timestamp = timestamp;
-            sentMessage.message = message;
+            sentMessage.message = dataMessage;
             if (destination) {
                 sentMessage.destination = destination;
             }
@@ -80,7 +81,6 @@ MessageSender.prototype = {
             syncMessage.sent = sentMessage;
             var contentMessage = new textsecure.protobuf.Content();
             contentMessage.syncMessage = syncMessage;
-
             return this.sendIndividualProto(myNumber, contentMessage, Date.now());
         }
     },
@@ -125,12 +125,13 @@ MessageSender.prototype = {
 
         return new Promise(function(resolve, reject) {
             this.sendMessageProto(timestamp, numbers, proto, function(res) {
+                res.dataMessage = proto.toArrayBuffer();
                 if (res.errors.length > 0)
                     reject(res);
                 else
                     resolve(res);
-            });
-        }.bind(this)).then(this.sendSyncMessage.bind(this, proto, timestamp));
+            }.bind(this));
+        }.bind(this));
     },
 
     sendMessageToNumber: function(number, messageText, attachments, timestamp) {
@@ -139,8 +140,12 @@ MessageSender.prototype = {
 
         return Promise.all(attachments.map(this.makeAttachmentPointer.bind(this))).then(function(attachmentsArray) {
             proto.attachments = attachmentsArray;
-            return this.sendIndividualProto(number, proto, timestamp).then(function() {
-                return this.sendSyncMessage(proto, timestamp, number);
+            return this.sendIndividualProto(number, proto, timestamp).then(function(res) {
+                res.dataMessage = proto.toArrayBuffer();
+                return res;
+            }.bind(this)).catch(function(res) {
+                res.dataMessage = proto.toArrayBuffer();
+                throw res;
             }.bind(this));
         }.bind(this));
     },
@@ -305,6 +310,7 @@ textsecure.MessageSender = function(url, username, password, attachment_server_u
     this.setGroupName                  = sender.setGroupName                 .bind(sender);
     this.setGroupAvatar                = sender.setGroupAvatar               .bind(sender);
     this.leaveGroup                    = sender.leaveGroup                   .bind(sender);
+    this.sendSyncMessage               = sender.sendSyncMessage              .bind(sender);
 };
 
 textsecure.MessageSender.prototype = {