diff --git a/src/services/helpers/hash.js b/src/services/helpers/hash.js
index ad933e48234..c978477058a 100644
--- a/src/services/helpers/hash.js
+++ b/src/services/helpers/hash.js
@@ -1,5 +1,4 @@
 const bcrypt = require('bcryptjs');
-const { promisify } = require('es6-promisify');
 const { BadRequest } = require('../../errors');
 const { userModel } = require('../user/model');
 const { getRandomInt } = require('../../utils/randomNumberGenerator');
@@ -43,21 +42,19 @@ const rndChar = () => {
 };
 
 module.exports = function setup() {
-	const genSaltAsync = promisify(bcrypt.genSalt);
-	const genHashAsync = promisify(bcrypt.hash);
 	class HashService {
 		constructor(options) {
 			this.options = options || {};
 			this.docs = {};
 		}
 
-		async create(data, params) {
+		async create(data) {
 			if (data.toHash === undefined) {
 				throw new BadRequest('Please set toHash key.');
 			}
-			const salt = await genSaltAsync(8);
+			const salt = await bcrypt.genSalt(8);
 
-			let hash = await genHashAsync(data.toHash, salt);
+			let hash = await bcrypt.hash(data.toHash, salt);
 
 			if (data.save === true || data.save === 'true') {
 				hash = hash.replace(/\/|\$|\./g, rndChar());
diff --git a/src/utils/redis.js b/src/utils/redis.js
index 550a728415e..1a8d085fc09 100644
--- a/src/utils/redis.js
+++ b/src/utils/redis.js
@@ -1,4 +1,3 @@
-const { promisify } = require('util');
 const Redis = require('ioredis');
 const { Configuration } = require('@hpi-schul-cloud/commons');
 
@@ -32,19 +31,19 @@ function setRedisClient(client) {
 }
 
 const redisGetAsync = (...args) => {
-	if (redisClient) return promisify(redisClient.get).apply(redisClient, args);
+	if (redisClient) return redisClient.get(...args);
 	throw new GeneralError('No redis connection. Check for this via getRedisClient().');
 };
 const redisSetAsync = (...args) => {
-	if (redisClient) return promisify(redisClient.set).apply(redisClient, args);
+	if (redisClient) return redisClient.set(...args);
 	throw new GeneralError('No redis connection. Check for this via getRedisClient().');
 };
 const redisDelAsync = (...args) => {
-	if (redisClient) return promisify(redisClient.del).apply(redisClient, args);
+	if (redisClient) return redisClient.del(...args);
 	throw new GeneralError('No redis connection. Check for this via getRedisClient().');
 };
 const redisTtlAsync = (...args) => {
-	if (redisClient) return promisify(redisClient.ttl).apply(redisClient, args);
+	if (redisClient) return redisClient.ttl(...args);
 	throw new GeneralError('No redis connection. Check for this via getRedisClient().');
 };
 
diff --git a/test/utils/redis/redisMock.js b/test/utils/redis/redisMock.js
index f0e6c19d40f..8bc84ef4fff 100644
--- a/test/utils/redis/redisMock.js
+++ b/test/utils/redis/redisMock.js
@@ -2,10 +2,9 @@ const valueDict = {};
 const ttlDict = {};
 
 const RedisClientMock = class {
-	get(key, ...args) {
+	get(key) {
 		const value = valueDict[key];
-		const callback = args[args.length - 1];
-		callback(null, value);
+		return Promise.resolve(value);
 	}
 
 	set(key, value, ...args) {
@@ -14,21 +13,18 @@ const RedisClientMock = class {
 		if (ex >= 0) {
 			ttlDict[key] = args[ex + 1];
 		}
-		const callback = args[args.length - 1];
-		callback(null, true);
+		return Promise.resolve(true);
 	}
 
-	del(key, ...args) {
+	del(key) {
 		delete valueDict[key];
 		delete ttlDict[key];
-		const callback = args[args.length - 1];
-		callback(null, true);
+		return Promise.resolve(true);
 	}
 
-	ttl(key, ...args) {
+	ttl(key) {
 		const ttl = ttlDict[key];
-		const callback = args[args.length - 1];
-		callback(null, ttl);
+		return Promise.resolve(ttl);
 	}
 };