diff --git a/matrix-util.js b/matrix-util.js
index 2137cf3..80e8105 100644
--- a/matrix-util.js
+++ b/matrix-util.js
@@ -1,6 +1,7 @@
 'use strict';
 
 var moment = require('moment');
+var momentFormat = 'YYYY-MM-DD HH:mm:ss';
 
 module.exports = MatrixUtil;
 
@@ -67,7 +68,7 @@ MatrixUtil.prototype.updateBuddyState = function(jid, state, statusText, resourc
         matrix.buddies[jid]['resources'][resource] = {
             state: state,
             statusText: statusText,
-            last_update: moment().format('YYYY-MM-DD HH:mm:ss')
+            last_update: moment().format(momentFormat)
         }
     }
     catch(e) {
@@ -142,7 +143,8 @@ MatrixUtil.prototype._updateLastMessage = function(partner, msg, direction) {
 
     matrix.buddies[partner]['last_' + direction] = {
         msg: msg,
-        last_update: moment().format('YYYY-MM-DD HH:mm:ss')
+        last_update: moment().format(momentFormat),
+        last_update_ts: Date.now()
     }
 }