diff --git a/src/becca/becca-interface.ts b/src/becca/becca-interface.ts
index 29c2d080e..48a096eda 100644
--- a/src/becca/becca-interface.ts
+++ b/src/becca/becca-interface.ts
@@ -242,7 +242,7 @@ export default class Becca {
         return (this as any)[camelCaseEntityName][entityId];
     }
 
-    getRecentNotesFromQuery(query: string, params = []): BRecentNote[] {
+    getRecentNotesFromQuery(query: string, params: string[] = []): BRecentNote[] {
         const rows = sql.getRows(query, params);
 
         const BRecentNote = require('./entities/brecent_note'); // avoiding circular dependency problems
diff --git a/src/routes/api/autocomplete.js b/src/routes/api/autocomplete.ts
similarity index 66%
rename from src/routes/api/autocomplete.js
rename to src/routes/api/autocomplete.ts
index 9ed36f89e..0aaa3f537 100644
--- a/src/routes/api/autocomplete.js
+++ b/src/routes/api/autocomplete.ts
@@ -1,21 +1,26 @@
 "use strict";
 
-const beccaService = require('../../becca/becca_service');
-const searchService = require('../../services/search/services/search');
-const log = require('../../services/log');
-const utils = require('../../services/utils');
-const cls = require('../../services/cls');
-const becca = require('../../becca/becca');
+import beccaService = require('../../becca/becca_service');
+import searchService = require('../../services/search/services/search');
+import log = require('../../services/log');
+import utils = require('../../services/utils');
+import cls = require('../../services/cls');
+import becca = require('../../becca/becca');
+import { Request } from 'express';
+import ValidationError = require('../../errors/validation_error');
 
-function getAutocomplete(req) {
-    const query = req.query.query.trim();
+function getAutocomplete(req: Request) {
+    if (typeof req.query.query !== "string") {
+        throw new ValidationError("Invalid query data type.");
+    }
+    const query = (req.query.query || "").trim();
     const activeNoteId = req.query.activeNoteId || 'none';
 
     let results;
 
     const timestampStarted = Date.now();
 
-    if (query.length === 0) {
+    if (query.length === 0 && typeof activeNoteId === "string") {
         results = getRecentNotes(activeNoteId);
     }
     else {
@@ -31,7 +36,7 @@ function getAutocomplete(req) {
     return results;
 }
 
-function getRecentNotes(activeNoteId) {
+function getRecentNotes(activeNoteId: string) {
     let extraCondition = '';
     const params = [activeNoteId];
 
@@ -70,6 +75,6 @@ function getRecentNotes(activeNoteId) {
     });
 }
 
-module.exports = {
+export = {
     getAutocomplete
 };
diff --git a/src/routes/routes.js b/src/routes/routes.js
index 269f2a6ae..27465e442 100644
--- a/src/routes/routes.js
+++ b/src/routes/routes.js
@@ -26,7 +26,7 @@ const treeApiRoute = require('./api/tree.js');
 const notesApiRoute = require('./api/notes.js');
 const branchesApiRoute = require('./api/branches.js');
 const attachmentsApiRoute = require('./api/attachments');
-const autocompleteApiRoute = require('./api/autocomplete.js');
+const autocompleteApiRoute = require('./api/autocomplete');
 const cloningApiRoute = require('./api/cloning');
 const revisionsApiRoute = require('./api/revisions');
 const recentChangesApiRoute = require('./api/recent_changes.js');