diff --git a/test/socket.io.js b/test/socket.io.js
index 333a9cea97..110258a0de 100644
--- a/test/socket.io.js
+++ b/test/socket.io.js
@@ -109,7 +109,7 @@ describe('socket.io', () => {
 
 	it('should return error for invalid eventName type', (done) => {
 		const eventName = ['topics.loadMoreTags'];
-		io.emit(eventName, function (err) {
+		io.emit(eventName, (err) => {
 			const eventAsString = String(eventName);
 			assert.strictEqual(err.message, `[[error:invalid-event, ${eventAsString}]]`);
 			done();