diff --git a/src/socket.io/topics/tags.js b/src/socket.io/topics/tags.js
index a8f86eee19..c5d2695692 100644
--- a/src/socket.io/topics/tags.js
+++ b/src/socket.io/topics/tags.js
@@ -68,6 +68,7 @@ module.exports = function (SocketTopics) {
 			}
 		}
 		data.cids = await categories.getCidsByPrivilege('categories:cid', uid, 'topics:read');
+		data.cids = data.cids.filter(cid => cid !== -1);
 		return await method(data);
 	}
 
@@ -106,7 +107,8 @@ module.exports = function (SocketTopics) {
 
 		const start = parseInt(data.after, 10);
 		const stop = start + 99;
-		const cids = await categories.getCidsByPrivilege('categories:cid', socket.uid, 'topics:read');
+		let cids = await categories.getCidsByPrivilege('categories:cid', socket.uid, 'topics:read');
+		cids = cids.filter(cid => cid !== -1);
 		const tags = await topics.getCategoryTagsData(cids, start, stop);
 		return { tags: tags.filter(Boolean), nextStart: stop + 1 };
 	};