diff --git a/public/src/client/topic/posts.js b/public/src/client/topic/posts.js
index c800704b79..b88dc73608 100644
--- a/public/src/client/topic/posts.js
+++ b/public/src/client/topic/posts.js
@@ -256,7 +256,7 @@ define('forum/topic/posts', [
 		const after = parseInt(afterEl.attr('data-index'), 10) || 0;
 
 		const tid = ajaxify.data.tid;
-		if (!utils.isNumber(tid) || !utils.isNumber(after) || (direction < 0 && components.get('post', 'index', 0).length)) {
+		if (!utils.isNumber(after) || (direction < 0 && components.get('post', 'index', 0).length)) {
 			return;
 		}
 
diff --git a/src/socket.io/topics/infinitescroll.js b/src/socket.io/topics/infinitescroll.js
index cb0814d329..7890500eb9 100644
--- a/src/socket.io/topics/infinitescroll.js
+++ b/src/socket.io/topics/infinitescroll.js
@@ -5,6 +5,7 @@ const privileges = require('../../privileges');
 const meta = require('../../meta');
 const utils = require('../../utils');
 const social = require('../../social');
+const activitypub = require('../../activitypub');
 
 module.exports = function (SocketTopics) {
 	SocketTopics.loadMore = async function (socket, data) {
@@ -21,7 +22,8 @@ module.exports = function (SocketTopics) {
 			throw new Error('[[error:no-privileges]]');
 		}
 
-		const set = data.topicPostSort === 'most_votes' ? `tid:${data.tid}:posts:votes` : `tid:${data.tid}:posts`;
+		const setPrefix = activitypub.helpers.isUri(data.tid) ? 'tidRemote' : 'tid';
+		const set = data.topicPostSort === 'most_votes' ? `${setPrefix}:${data.tid}:posts:votes` : `${setPrefix}:${data.tid}:posts`;
 		const reverse = data.topicPostSort === 'newest_to_oldest' || data.topicPostSort === 'most_votes';
 		let start = Math.max(0, parseInt(data.after, 10));