diff --git a/src/dummy.js b/src/dummy.js
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/src/topics/suggested.js b/src/topics/suggested.js
index bc8bbd2102..449ab6a196 100644
--- a/src/topics/suggested.js
+++ b/src/topics/suggested.js
@@ -1,79 +1,68 @@
-
-'use strict';
-
-const _ = require('lodash');
-
-const db = require('../database');
-const user = require('../user');
-const privileges = require('../privileges');
-const plugins = require('../plugins');
-
-module.exports = function (Topics) {
-	Topics.getSuggestedTopics = async function (tid, uid, start, stop, cutoff = 0) {
-		let tids;
-		if (!tid) {
-			return [];
-		}
-		tid = String(tid);
-		cutoff = cutoff === 0 ? cutoff : (cutoff * 2592000000);
-		const { cid, title, tags } = await Topics.getTopicFields(tid, [
-			'cid', 'title', 'tags',
-		]);
-
-		const [tagTids, searchTids] = await Promise.all([
-			getTidsWithSameTags(tid, tags.map(t => t.value), cutoff),
-			getSearchTids(tid, title, cid, cutoff),
-		]);
-
-		tids = _.uniq(tagTids.concat(searchTids));
-
-		let categoryTids = [];
-		if (stop !== -1 && tids.length < stop - start + 1) {
-			categoryTids = await getCategoryTids(tid, cid, cutoff);
-		}
-		tids = _.shuffle(_.uniq(tids.concat(categoryTids)));
-		tids = await privileges.topics.filterTids('topics:read', tids, uid);
-
-		let topicData = await Topics.getTopicsByTids(tids, uid);
-		topicData = topicData.filter(topic => topic && String(topic.tid) !== tid);
-		topicData = await user.blocks.filter(uid, topicData);
-		topicData = topicData.slice(start, stop !== -1 ? stop + 1 : undefined)
-			.sort((t1, t2) => t2.timestamp - t1.timestamp);
-		Topics.calculateTopicIndices(topicData, start);
-		return topicData;
-	};
-
-	async function getTidsWithSameTags(tid, tags, cutoff) {
-		let tids = cutoff === 0 ?
-			await db.getSortedSetRevRange(tags.map(tag => `tag:${tag}:topics`), 0, -1) :
-			await db.getSortedSetRevRangeByScore(tags.map(tag => `tag:${tag}:topics`), 0, -1, '+inf', Date.now() - cutoff);
-		tids = tids.filter(_tid => _tid !== tid); // remove self
-		return _.shuffle(_.uniq(tids)).slice(0, 10);
-	}
-
-	async function getSearchTids(tid, title, cid, cutoff) {
-		let { ids: tids } = await plugins.hooks.fire('filter:search.query', {
-			index: 'topic',
-			content: title,
-			matchWords: 'any',
-			cid: [cid],
-			limit: 20,
-			ids: [],
-		});
-		tids = tids.filter(_tid => String(_tid) !== tid); // remove self
-		if (cutoff) {
-			const topicData = await Topics.getTopicsFields(tids, ['tid', 'timestamp']);
-			const now = Date.now();
-			tids = topicData.filter(t => t && t.timestamp > now - cutoff).map(t => t.tid);
-		}
-
-		return _.shuffle(tids).slice(0, 10).map(String);
-	}
-
-	async function getCategoryTids(tid, cid, cutoff) {
-		const tids = cutoff === 0 ?
-			await db.getSortedSetRevRange(`cid:${cid}:tids:lastposttime`, 0, 9) :
-			await db.getSortedSetRevRangeByScore(`cid:${cid}:tids:lastposttime`, 0, 10, '+inf', Date.now() - cutoff);
-		return _.shuffle(tids.filter(_tid => _tid !== tid));
-	}
+"use strict";
+var __importDefault = (this && this.__importDefault) || function (mod) {
+    return (mod && mod.__esModule) ? mod : { "default": mod };
 };
+/* eslint-disable @typescript-eslint/no-unsafe-member-access */
+/* eslint-disable @typescript-eslint/no-unsafe-call */
+const lodash_1 = __importDefault(require("lodash"));
+const database_1 = __importDefault(require("../database"));
+const user_1 = __importDefault(require("../user"));
+const privileges_1 = __importDefault(require("../privileges"));
+const plugins_1 = __importDefault(require("../plugins"));
+function Suggested(Topics) {
+    async function getTidsWithSameTags(tid, tags, cutoff) {
+        const tids = cutoff === 0 ?
+            await (database_1.default === null || database_1.default === void 0 ? void 0 : database_1.default.getSortedSetRevRange(tags.map(tag => `tag:${tag}:topics`), 0, -1)) :
+            await (database_1.default === null || database_1.default === void 0 ? void 0 : database_1.default.getSortedSetRevRangeByScore(tags.map(tag => `tag:${tag}:topics`), 0, -1, '+inf', Date.now() - cutoff));
+        return lodash_1.default.shuffle(lodash_1.default.uniq((await tids).filter((_tid) => _tid !== tid))).slice(0, 10);
+    }
+    async function getSearchTids(tid, title, cid, cutoff, uid) {
+        const { ids: tids } = await plugins_1.default.hooks.fire('filter:search.query', {
+            index: 'topic',
+            content: title,
+            matchWords: 'any',
+            cid: [cid],
+            limit: 20,
+            ids: [],
+        });
+        const filteredTids = tids.filter(_tid => _tid !== tid);
+        if (cutoff) {
+            const topicData = await Topics.getTopicsByTids(filteredTids, uid);
+            const now = Date.now();
+            return lodash_1.default.shuffle(topicData.filter(t => t && t.timestamp > now - cutoff).map(t => t.tid)).slice(0, 10);
+        }
+        return lodash_1.default.shuffle(filteredTids).slice(0, 10);
+    }
+    async function getCategoryTids(tid, cid, cutoff) {
+        const tids = cutoff === 0 ?
+            await (database_1.default === null || database_1.default === void 0 ? void 0 : database_1.default.getSortedSetRevRange(`cid:${cid}:tids:lastposttime`, 0, 9)) :
+            await (database_1.default === null || database_1.default === void 0 ? void 0 : database_1.default.getSortedSetRevRangeByScore(`cid:${cid}:tids:lastposttime`, 0, 10, '+inf', Date.now() - cutoff));
+        return lodash_1.default.shuffle((await tids).filter((_tid) => _tid !== tid));
+    }
+    Topics.getSuggestedTopics = async function (tid, uid, start, stop, cutoff = 0) {
+        if (!tid)
+            return [];
+        tid = String(tid);
+        cutoff = cutoff === 0 ? cutoff : cutoff * 2592000000;
+        const { cid, title, tags } = await Topics.getTopicFields(tid, ['cid', 'title', 'tags']);
+        const [tagTids, searchTids] = await Promise.all([
+            getTidsWithSameTags(tid, tags.map(t => t.value), cutoff),
+            getSearchTids(tid, title, cid, cutoff, uid),
+        ]);
+        let tids = lodash_1.default.uniq([...tagTids, ...searchTids]);
+        let categoryTids = [];
+        if (stop !== -1 && (tids).length < stop - start + 1) {
+            categoryTids = await getCategoryTids(tid, cid, cutoff);
+        }
+        tids = lodash_1.default.shuffle(lodash_1.default.uniq([...tids, ...categoryTids]));
+        tids = await privileges_1.default.topics.filterTids('topics:read', tids, uid);
+        let topicData = await Topics.getTopicsByTids(tids, uid);
+        topicData = topicData.filter(topic => topic && topic.tid !== tid);
+        topicData = await user_1.default.blocks.filter(uid, topicData);
+        topicData = topicData.slice(start, stop !== -1 ? stop + 1 : undefined)
+            .sort((t1, t2) => t2.timestamp - t1.timestamp);
+        Topics.calculateTopicIndices(topicData, start);
+        return topicData;
+    };
+}
+module.exports = Suggested;
diff --git a/src/topics/suggested.ts b/src/topics/suggested.ts
new file mode 100644
index 0000000000..2bc031664c
--- /dev/null
+++ b/src/topics/suggested.ts
@@ -0,0 +1,112 @@
+/* eslint-disable @typescript-eslint/no-unsafe-member-access */
+/* eslint-disable @typescript-eslint/no-unsafe-call */
+import _ from 'lodash';
+import db from '../database';
+import user from '../user';
+import privileges from '../privileges';
+import plugins from '../plugins';
+
+interface Topic {
+  tid: string;
+  timestamp: number;
+}
+
+interface TopicFields {
+  cid: string;
+  title: string;
+  tags: { value: string }[];
+}
+
+interface TopicsType {
+  getTopicFields: (tid: string, fields: string[]) => Promise<TopicFields>;
+  getTopicsByTids: (tids: string[], uid: string) => Promise<Topic[]>;
+  calculateTopicIndices: (topics: Topic[], start: number) => void;
+  getSuggestedTopics?: (
+    tid: string,
+    uid: string,
+    start: number,
+    stop: number,
+    cutoff?: number
+  ) => Promise<Topic[]>;
+}
+
+function Suggested(Topics: TopicsType) {
+	async function getTidsWithSameTags(tid: string, tags: string[], cutoff: number): Promise<string[]> {
+		const tids = cutoff === 0 ?
+			await db?.getSortedSetRevRange(tags.map(tag => `tag:${tag}:topics`), 0, -1) as Promise<string[]> :
+			await db?.getSortedSetRevRangeByScore(tags.map(tag => `tag:${tag}:topics`), 0, -1, '+inf', Date.now() - cutoff) as Promise<string[]>;
+
+		return _.shuffle(_.uniq((await tids).filter((_tid: string) => _tid !== tid))).slice(0, 10);
+	}
+
+	async function getSearchTids(
+		tid: string, title: string, cid: string, cutoff: number, uid: string
+	): Promise<string[]> {
+		const { ids: tids } = await plugins.hooks.fire('filter:search.query', {
+			index: 'topic',
+			content: title,
+			matchWords: 'any',
+			cid: [cid],
+			limit: 20,
+			ids: [],
+		}) as { ids: string[] };
+
+		const filteredTids = tids.filter(_tid => _tid !== tid);
+
+		if (cutoff) {
+			const topicData = await Topics.getTopicsByTids(filteredTids, uid);
+			const now = Date.now();
+			return _.shuffle(
+				topicData.filter(t => t && t.timestamp > now - cutoff).map(t => t.tid)
+			).slice(0, 10);
+		}
+
+		return _.shuffle(filteredTids).slice(0, 10);
+	}
+
+	async function getCategoryTids(tid: string, cid: string, cutoff: number): Promise<string[]> {
+		const tids = cutoff === 0 ?
+			await db?.getSortedSetRevRange(`cid:${cid}:tids:lastposttime`, 0, 9) as Promise<string[]> :
+			await db?.getSortedSetRevRangeByScore(`cid:${cid}:tids:lastposttime`, 0, 10, '+inf', Date.now() - cutoff) as Promise<string[]>;
+
+		return _.shuffle((await tids).filter((_tid: string) => _tid !== tid));
+	}
+
+	Topics.getSuggestedTopics = async function (
+		tid: string,
+		uid: string,
+		start: number,
+		stop: number,
+		cutoff = 0
+	): Promise<Topic[]> {
+		if (!tid) return [];
+
+		tid = String(tid);
+		cutoff = cutoff === 0 ? cutoff : cutoff * 2592000000;
+		const { cid, title, tags } = await Topics.getTopicFields(tid, ['cid', 'title', 'tags']);
+
+		const [tagTids, searchTids] = await Promise.all([
+			getTidsWithSameTags(tid, tags.map(t => t.value), cutoff),
+			getSearchTids(tid, title, cid, cutoff, uid),
+		]);
+
+		let tids = _.uniq([...tagTids, ...searchTids]);
+
+		let categoryTids: string[] = [];
+		if (stop !== -1 && (tids).length < stop - start + 1) {
+			categoryTids = await getCategoryTids(tid, cid, cutoff);
+		}
+		tids = _.shuffle(_.uniq([...tids, ...categoryTids]));
+		tids = await privileges.topics.filterTids('topics:read', tids, uid) as string[];
+
+		let topicData = await Topics.getTopicsByTids(tids, uid);
+		topicData = topicData.filter(topic => topic && topic.tid !== tid);
+		topicData = await user.blocks.filter(uid, topicData) as Topic[];
+		topicData = topicData.slice(start, stop !== -1 ? stop + 1 : undefined)
+			.sort((t1, t2) => t2.timestamp - t1.timestamp);
+		Topics.calculateTopicIndices(topicData, start);
+		return topicData;
+	};
+}
+
+export = Suggested
diff --git a/tsconfig.json b/tsconfig.json
index 10aeeef7e6..c15cb37711 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,7 +1,7 @@
 {
   "compilerOptions": {
     "allowJs": false,
-    "target": "es6",
+    "target": "es2017",
     "module": "commonjs",
     "moduleResolution": "node",
     "esModuleInterop": true,