diff --git a/Gruntfile.js b/Gruntfile.js
index 8a8a73ca..3f7043d4 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -18,7 +18,7 @@ module.exports = function(grunt) {
           browserifyOptions: {
             standalone: 'openpgp'
           },
-          external: [ 'crypto', 'node-localstorage' ]
+          external: [ 'crypto', 'node-localstorage', 'node-fetch' ]
         }
       },
       openpgp_debug: {
@@ -30,7 +30,7 @@ module.exports = function(grunt) {
             debug: true,
             standalone: 'openpgp'
           },
-          external: [ 'crypto', 'node-localstorage' ]
+          external: [ 'crypto', 'node-localstorage', 'node-fetch' ]
         }
       },
       worker: {
@@ -48,7 +48,7 @@ module.exports = function(grunt) {
           'test/lib/unittests-bundle.js': [ './test/unittests.js' ]
         },
         options: {
-          external: ['crypto', 'node-localstorage', 'openpgp', '../../../dist/openpgp', '../../dist/openpgp']
+          external: [ 'crypto', 'node-localstorage', 'node-fetch', 'openpgp', '../../dist/openpgp', '../../../dist/openpgp' ]
         }
       }
     },
diff --git a/src/hkp/hkp.js b/src/hkp/hkp.js
index fd764fe0..01063ec7 100644
--- a/src/hkp/hkp.js
+++ b/src/hkp/hkp.js
@@ -31,14 +31,10 @@ var config = require('../config');
  * @constructor
  * @param {String}    keyServerBaseUrl  (optional) The HKP key server base url including
  *   the protocol to use e.g. https://pgp.mit.edu
- * @param {function}  fetch             (optional) The fetch function is an easier way
- *   to make web requests and handle responses than using an XMLHttpRequest. You can
- *   pass in a custom implementaion or just leave the parameter empty to fall back to
- *   window.fetch (https://fetch.spec.whatwg.org).
  */
-function HKP(keyServerBaseUrl, fetch) {
+function HKP(keyServerBaseUrl) {
   this._baseUrl = keyServerBaseUrl ? keyServerBaseUrl : config.keyserver;
-  this._fetch = fetch ? fetch : typeof window !== 'undefined' && window.fetch;
+  this._fetch = typeof window !== 'undefined' ? window.fetch : require('node-fetch');
 }
 
 /**
diff --git a/test/general/hkp.js b/test/general/hkp.js
index 568e4a89..d1f9549e 100644
--- a/test/general/hkp.js
+++ b/test/general/hkp.js
@@ -1,7 +1,6 @@
 'use strict';
 
 var openpgp = typeof window !== 'undefined' && window.openpgp ? window.openpgp : require('../../dist/openpgp');
-var fetch = typeof window !== 'undefined' ? window.fetch : require('node-fetch');
 
 var chai = require('chai'),
   expect = chai.expect;
@@ -108,7 +107,7 @@ describe('HKP unit tests', function() {
       '-----END PGP PUBLIC KEY BLOCK-----';
 
   beforeEach(function() {
-    hkp = new openpgp.HKP(openpgp.config.keyserver, fetch);
+    hkp = new openpgp.HKP(openpgp.config.keyserver);
   });
 
   afterEach(function() {});