diff --git a/js/ui/components/telepathyClient.js b/js/ui/components/telepathyClient.js
index e6ae34042..cdb7f57f5 100644
--- a/js/ui/components/telepathyClient.js
+++ b/js/ui/components/telepathyClient.js
@@ -2,7 +2,6 @@
 /* exported Component */
 
 const { Clutter, Gio, GLib, GObject, St } = imports.gi;
-const Lang = imports.lang;
 
 var Tpl = null;
 var Tp = null;
@@ -630,11 +629,19 @@ class ChatSource extends MessageTray.Source {
     }
 }) : null;
 
+const ChatNotificationMessage = HAVE_TP ? GObject.registerClass(
+class ChatNotificationMessage extends GObject.Object {
+    _init(props = {}) {
+        super._init();
+        this.set(props);
+    }
+}) : null;
+
 var ChatNotification = HAVE_TP ? GObject.registerClass({
     Signals: {
-        'message-removed': { param_types: [Tp.Message.$gtype] },
-        'message-added': { param_types: [Tp.Message.$gtype] },
-        'timestamp-changed': { param_types: [Tp.Message.$gtype] },
+        'message-removed': { param_types: [ChatNotificationMessage.$gtype] },
+        'message-added': { param_types: [ChatNotificationMessage.$gtype] },
+        'timestamp-changed': { param_types: [ChatNotificationMessage.$gtype] },
     },
 }, class ChatNotification extends MessageTray.Notification {
     _init(source) {
@@ -735,21 +742,24 @@ var ChatNotification = HAVE_TP ? GObject.registerClass({
                                       styles: [],
                                       timestamp: currentTime,
                                       noTimestamp: false });
+        const { noTimestamp } = props;
+        delete props.noTimestamp;
 
         // Reset the old message timeout
         if (this._timestampTimeoutId)
             GLib.source_remove(this._timestampTimeoutId);
         this._timestampTimeoutId = 0;
 
-        let message = { realMessage: props.group != 'meta',
-                        showTimestamp: false };
-        Lang.copyProperties(props, message);
-        delete message.noTimestamp;
+        let message = new ChatNotificationMessage({
+            realMessage: props.group !== 'meta',
+            showTimestamp: false,
+            ...props,
+        });
 
         this.messages.unshift(message);
         this.emit('message-added', message);
 
-        if (!props.noTimestamp) {
+        if (!noTimestamp) {
             let timestamp = props.timestamp;
             if (timestamp < currentTime - SCROLLBACK_IMMEDIATE_TIME) {
                 this.appendTimestamp();