diff --git a/lib/models/user.js b/lib/models/user.js
index 26a557a77..383be1a72 100644
--- a/lib/models/user.js
+++ b/lib/models/user.js
@@ -1,15 +1,6 @@
 'use strict'
 // external modules
 const Sequelize = require('sequelize')
-const crypto = require('crypto')
-if (!crypto.scrypt) {
-  // polyfill for node.js 8.0, see https://github.com/chrisveness/scrypt-kdf#openssl-implementation
-  const scryptAsync = require('scrypt-async')
-  crypto.scrypt = function (password, salt, keylen, options, callback) {
-    const opt = Object.assign({}, options, { dkLen: keylen })
-    scryptAsync(password, salt, opt, (derivedKey) => callback(null, Buffer.from(derivedKey)))
-  }
-}
 const scrypt = require('scrypt-kdf')
 
 // core