diff --git a/src/socket.io/topics/unread.js b/src/socket.io/topics/unread.js
index e997e1608d..0d8021a398 100644
--- a/src/socket.io/topics/unread.js
+++ b/src/socket.io/topics/unread.js
@@ -67,6 +67,7 @@ module.exports = function (SocketTopics) {
 			await topics.markAsUnreadForAll(tid);
 			await topics.updateRecent(tid, now);
 			await db.sortedSetAdd('cid:' + topicData.cid + ':tids:lastposttime', now, tid);
+			await topics.setTopicField(tid, 'lastposttime', now);
 		}));
 		topics.pushUnreadCount(socket.uid);
 	};