diff --git a/src/topics/unread.js b/src/topics/unread.js
index 41385318a4..7ad5a5e709 100644
--- a/src/topics/unread.js
+++ b/src/topics/unread.js
@@ -169,7 +169,7 @@ module.exports = function(Topics) {
 			return parseInt(value, 10) !== 0;
 		});
 
-		async.each(uids, function(uid, next) {
+		async.eachLimit(uids, 5, function(uid, next) {
 			Topics.getTotalUnread(uid, function(err, count) {
 				websockets.in('uid_' + uid).emit('event:unread.updateCount', null, count);
 				next();