diff --git a/src/topics/tags.js b/src/topics/tags.js
index 192d5e8a26..88a8f3a69b 100644
--- a/src/topics/tags.js
+++ b/src/topics/tags.js
@@ -152,12 +152,15 @@ module.exports = function (Topics) {
 	};
 
 	Topics.getTopicTags = async function (tid) {
-		return await db.getSetMembers('topic:' + tid + ':tags');
+		const tags = await db.getSetMembers('topic:' + tid + ':tags');
+		return tags.sort();
 	};
 
 	Topics.getTopicsTags = async function (tids) {
 		const keys = tids.map(tid => 'topic:' + tid + ':tags');
-		return await db.getSetsMembers(keys);
+		const tags = await db.getSetsMembers(keys);
+		tags.forEach(tags => tags.sort());
+		return tags;
 	};
 
 	Topics.getTopicTagsObjects = async function (tid) {
@@ -192,6 +195,31 @@ module.exports = function (Topics) {
 		return topicTags;
 	};
 
+	Topics.addTags = async function (tags, tids) {
+		const topicData = await Topics.getTopicsFields(tids, ['timestamp']);
+		const sets = tids.map(tid => 'topic:' + tid + ':tags');
+		for (let i = 0; i < tags.length; i++) {
+			/* eslint-disable no-await-in-loop */
+			await Promise.all([
+				db.setsAdd(sets, tags[i]),
+				db.sortedSetAdd('tag:' + tags[i] + ':topics', topicData.map(t => t.timestamp), tids),
+			]);
+			await updateTagCount(tags[i]);
+		}
+	};
+
+	Topics.removeTags = async function (tags, tids) {
+		const sets = tids.map(tid => 'topic:' + tid + ':tags');
+		for (let i = 0; i < tags.length; i++) {
+			/* eslint-disable no-await-in-loop */
+			await Promise.all([
+				db.setsRemove(sets, tags[i]),
+				db.sortedSetRemove('tag:' + tags[i] + ':topics', tids),
+			]);
+			await updateTagCount(tags[i]);
+		}
+	};
+
 	Topics.updateTopicTags = async function (tid, tags) {
 		await Topics.deleteTopicTags(tid);
 		const timestamp = await Topics.getTopicField(tid, 'timestamp');
diff --git a/test/topics.js b/test/topics.js
index 682ce72025..80380b5a3d 100644
--- a/test/topics.js
+++ b/test/topics.js
@@ -1753,6 +1753,19 @@ describe('Topic\'s', function () {
 				});
 			});
 		});
+
+		it('should add and remove tags from topics properly', async () => {
+			const result = await topics.post({ uid: adminUid, tags: ['tag4', 'tag2', 'tag1', 'tag3'], title: 'tag topic', content: 'topic 1 content', cid: topic.categoryId });
+			const tid = result.topicData.tid;
+			let tags = await topics.getTopicTags(tid);
+			assert.deepStrictEqual(tags, ['tag1', 'tag2', 'tag3', 'tag4']);
+			await topics.addTags(['tag7', 'tag6', 'tag5'], [tid]);
+			tags = await topics.getTopicTags(tid);
+			assert.deepStrictEqual(tags, ['tag1', 'tag2', 'tag3', 'tag4', 'tag5', 'tag6', 'tag7']);
+			await topics.removeTags(['tag1', 'tag3', 'tag5', 'tag7'], [tid]);
+			tags = await topics.getTopicTags(tid);
+			assert.deepStrictEqual(tags, ['tag2', 'tag4', 'tag6']);
+		});
 	});
 
 	describe('follow/unfollow', function () {