diff --git a/cloudron.js b/cloudron.js
index 94dd766..a619f47 100644
--- a/cloudron.js
+++ b/cloudron.js
@@ -230,9 +230,19 @@ Cloudron.prototype.uninstallApp = function (appId) {
     assert(false, 'uninstallApp failed');
 };
 
-Cloudron.prototype.updateApp = function (appId, newManifest) {
+Cloudron.prototype.updateApp = function (appId, manifestOrAppstoreId) {
     process.stdout.write('Trying to update');
-    var res = request.post(this._origin + '/api/v1/apps/' + appId + '/update').query({ access_token: this._credentials.accessToken }).send({ password: this._credentials.password, manifest: newManifest }).end();
+
+    var data = {
+        password: this._credentials.password,
+        manifest: typeof manifestOrAppstoreId === 'object' ? manifestOrAppstoreId : null,
+        appStoreId: typeof manifestOrAppstoreId === 'string' ? manifestOrAppstoreId : null
+    };
+
+    var res = request.post(this._origin + '/api/v1/apps/' + appId + '/update')
+                .query({ access_token: this._credentials.accessToken })
+                .send(data)
+                .end();
     common.verifyResponse2xx(res, 'Could not update');
 
     console.log('Update started'.green);
diff --git a/test/app-update-test.js b/test/app-update-test.js
index 0eac63f..de9d027 100644
--- a/test/app-update-test.js
+++ b/test/app-update-test.js
@@ -6,10 +6,8 @@
 'use strict';
 
 var AppStore = require('../appstore.js'),
-    assert = require('assert'),
     Cloudron = require('../cloudron.js'),
-    common = require('../common.js'),
-    request = require('superagent-sync');
+    common = require('../common.js');
 
 require('colors');
 
@@ -57,13 +55,11 @@ describe('Application update test', function () {
 
     var location = 'test' + (Math.random() * 10000).toFixed();
     it('can install app', function () {
-        var manifest = appStore.getManifest(APP_ID, APP_OLD_VERSION);
-        appId = cloudron.installApp(location, manifest);
+        appId = cloudron.installApp(location, APP_ID + '@' + APP_OLD_VERSION);
     });
 
     it('update the app', function () {
-        var manifest = appStore.getManifest(APP_ID, APP_NEW_VERSION);
-        cloudron.updateApp(appId, manifest);
+        cloudron.updateApp(appId, APP_ID + '@' + APP_NEW_VERSION);
     });
 
     it('can uninstall app', function () {