diff --git a/lang/js/BrowserTestExtension/tests/startup.js b/lang/js/BrowserTestExtension/tests/startup.js
index 34333e6b..c1c576cc 100644
--- a/lang/js/BrowserTestExtension/tests/startup.js
+++ b/lang/js/BrowserTestExtension/tests/startup.js
@@ -1,47 +1,59 @@
 /* gpgme.js - Javascript integration for gpgme
  * Copyright (C) 2018 Bundesamt für Sicherheit in der Informationstechnik
  *
  * This file is part of GPGME.
  *
  * GPGME is free software; you can redistribute it and/or modify it
  * under the terms of the GNU Lesser General Public License as
  * published by the Free Software Foundation; either version 2.1 of
  * the License, or (at your option) any later version.
  *
  * GPGME is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this program; if not, see <https://www.gnu.org/licenses/>.
  * SPDX-License-Identifier: LGPL-2.1+
  *
  * Author(s):
  *     Maximilian Krambach <mkrambach@intevation.de>
  */
 
 /* global describe, it, expect, Gpgmejs, inputvalues */
 
 describe('GPGME context', function (){
     it('Starting a GpgME instance', function (done){
         let prm = Gpgmejs.init({ timeout: 2000 });
         const input = inputvalues.someInputParameter;
         prm.then(
             function (context){
                 expect(context).to.be.an('object');
                 expect(context.encrypt).to.be.a('function');
                 expect(context.decrypt).to.be.a('function');
                 expect(context.sign).to.be.a('function');
                 expect(context.verify).to.be.a('function');
                 context.Keyring = input;
                 expect(context.Keyring).to.be.an('object');
                 expect(context.Keyring).to.not.equal(input);
                 expect(context.Keyring.getKeys).to.be.a('function');
                 expect(context.Keyring.getDefaultKey).to.be.a('function');
                 expect(context.Keyring.importKey).to.be.a('function');
                 expect(context.Keyring.generateKey).to.be.a('function');
                 done();
             });
     });
+
+    it('Error message on unsuccessful connection (timeout)', function (done) {
+        let prm = Gpgmejs.init({ timeout: 1 });
+        prm.then(
+            null,
+            function (error){
+                expect(error).to.be.an('error');
+                expect(error.code).to.equal('CONN_TIMEOUT');
+                done();
+            }
+        );
+    });
 });
\ No newline at end of file
diff --git a/lang/js/src/Connection.js b/lang/js/src/Connection.js
index 923698a4..e9ab3b13 100644
--- a/lang/js/src/Connection.js
+++ b/lang/js/src/Connection.js
@@ -1,342 +1,352 @@
 /* gpgme.js - Javascript integration for gpgme
  * Copyright (C) 2018 Bundesamt für Sicherheit in der Informationstechnik
  *
  * This file is part of GPGME.
  *
  * GPGME is free software; you can redistribute it and/or modify it
  * under the terms of the GNU Lesser General Public License as
  * published by the Free Software Foundation; either version 2.1 of
  * the License, or (at your option) any later version.
  *
  * GPGME is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this program; if not, see <https://www.gnu.org/licenses/>.
  * SPDX-License-Identifier: LGPL-2.1+
  *
  * Author(s):
  *     Maximilian Krambach <mkrambach@intevation.de>
  */
 
 /* global chrome */
 
 import { permittedOperations } from './permittedOperations';
 import { gpgme_error } from './Errors';
 import { GPGME_Message, createMessage } from './Message';
 import { decode, atobArray, Utf8ArrayToStr } from './Helpers';
 
 /**
  * A Connection handles the nativeMessaging interaction via a port. As the
  * protocol only allows up to 1MB of message sent from the nativeApp to the
  * browser, the connection will stay open until all parts of a communication
  * are finished. For a new request, a new port will open, to avoid mixing
  * contexts.
  * @class
  * @private
  */
 export class Connection{
 
     constructor (){
         this._connectionError = null;
         this._connection = chrome.runtime.connectNative('gpgmejson');
         this._connection.onDisconnect.addListener(() => {
             if (chrome.runtime.lastError) {
                 this._connectionError = chrome.runtime.lastError.message;
             } else {
                 this._connectionError = 'Disconnected without error message';
             }
         });
     }
 
     /**
      * Immediately closes an open port.
      */
     disconnect () {
         if (this._connection){
             this._connection.disconnect();
             this._connection = null;
             this._connectionError = 'Disconnect requested by gpgmejs';
         }
     }
 
     /**
      * Checks if the connection terminated with an error state
      */
     get isDisconnected (){
         return this._connectionError !== null;
     }
 
     /**
     * @typedef {Object} backEndDetails
     * @property {String} gpgme Version number of gpgme
     * @property {Array<Object>} info Further information about the backend
     * and the used applications (Example:
     * <pre>
     * {
     *          "protocol":     "OpenPGP",
     *          "fname":        "/usr/bin/gpg",
     *          "version":      "2.2.6",
     *          "req_version":  "1.4.0",
     *          "homedir":      "default"
     * }
     * </pre>
     */
 
     /**
      * Retrieves the information about the backend.
      * @param {Boolean} details (optional) If set to false, the promise will
      *  just return if a connection was successful.
      * @param {Number} timeout (optional)
      * @returns {Promise<backEndDetails>|Promise<Boolean>} Details from the
      * backend
      * @async
      */
     checkConnection (details = true, timeout = 1000){
         if (typeof timeout !== 'number' && timeout <= 0) {
             timeout = 1000;
         }
         const msg = createMessage('version');
-        if (details === true) {
-            return this.post(msg);
-        } else {
-            let me = this;
-            return new Promise(function (resolve) {
-                Promise.race([
-                    me.post(msg),
-                    new Promise(function (resolve, reject){
-                        setTimeout(function (){
-                            reject(gpgme_error('CONN_TIMEOUT'));
-                        }, timeout);
-                    })
-                ]).then(function (){ // success
+        const prm = Promise.race([
+            this.post(msg),
+            new Promise(function (resolve, reject){
+                setTimeout(function (){
+                    reject(gpgme_error('CONN_TIMEOUT'));
+                }, timeout);
+            })
+        ]);
+        return new Promise( function (resolve, reject) {
+            prm.then(function (success){
+                if (details === true ) {
+                    resolve(success);
+                } else {
                     resolve(true);
-                }, function (){ // failure
+                }
+            }, function (error) {
+                if (details === true ) {
+                    reject(error);
+                } else {
                     resolve(false);
-                });
+                }
             });
-        }
+        });
     }
 
     /**
      * Sends a {@link GPGME_Message} via the nativeMessaging port. It
      * resolves with the completed answer after all parts have been
      * received and reassembled, or rejects with an {@link GPGME_Error}.
      *
      * @param {GPGME_Message} message
      * @returns {Promise<*>} The collected answer, depending on the messages'
      * operation
      * @private
      * @async
      */
     post (message){
         if (!message || !(message instanceof GPGME_Message)){
             this.disconnect();
             return Promise.reject(gpgme_error(
                 'PARAM_WRONG', 'Connection.post'));
         }
         if (message.isComplete() !== true){
             this.disconnect();
             return Promise.reject(gpgme_error('MSG_INCOMPLETE'));
         }
-        if (this.isDisconnected) {
-            if ( this.isNativeHostUnknown === true) {
-                return Promise.reject(gpgme_error('CONN_NO_CONFIG'));
-            } else {
-                return Promise.reject(gpgme_error(
-                    'CONN_NO_CONNECT', this._connectionError));
-            }
-        }
         let chunksize = message.chunksize;
         const me = this;
         const nativeCommunication = new Promise(function (resolve, reject){
             let answer = new Answer(message);
             let listener = function (msg) {
                 if (!msg){
                     me._connection.onMessage.removeListener(listener);
                     me._connection.disconnect();
                     reject(gpgme_error('CONN_EMPTY_GPG_ANSWER'));
                 } else {
                     let answer_result = answer.collect(msg);
                     if (answer_result !== true){
                         me._connection.onMessage.removeListener(listener);
                         me._connection.disconnect();
                         reject(answer_result);
                     } else {
                         if (msg.more === true){
                             me._connection.postMessage({
                                 'op': 'getmore',
                                 'chunksize': chunksize
                             });
                         } else {
                             me._connection.onMessage.removeListener(listener);
                             me._connection.disconnect();
                             const message = answer.getMessage();
                             if (message instanceof Error){
                                 reject(message);
                             } else {
                                 resolve(message);
                             }
                         }
                     }
                 }
             };
             me._connection.onMessage.addListener(listener);
             me._connection.postMessage(message.message);
+
+            // check for browser messaging errors after a while
+            // (browsers' extension permission checks take some time)
+            setTimeout( () => {
+                if (me.isDisconnected) {
+                    if ( me.isNativeHostUnknown === true) {
+                        return reject(gpgme_error('CONN_NO_CONFIG'));
+                    } else {
+                        return reject(gpgme_error(
+                            'CONN_NO_CONNECT', me._connectionError));
+                    }
+                }
+            }, 25);
+
         });
         if (permittedOperations[message.operation].pinentry === true) {
             return nativeCommunication;
         } else {
             return Promise.race([
                 nativeCommunication,
                 new Promise(function (resolve, reject){
                     setTimeout(function (){
-                        me._connection.disconnect();
+                        me.disconnect();
                         reject(gpgme_error('CONN_TIMEOUT'));
                     }, 5000);
                 })
             ]);
         }
     }
 }
 
 
 /**
  * A class for answer objects, checking and processing the return messages of
  * the nativeMessaging communication.
  * @private
  */
 class Answer{
 
     /**
      * @param {GPGME_Message} message
      */
     constructor (message){
         this._operation = message.operation;
         this._expected = message.expected;
         this._response_b64 = null;
     }
 
     get operation (){
         return this._operation;
     }
 
     get expected (){
         return this._expected;
     }
 
     /**
      * Checks if an error matching browsers 'host not known' messages occurred
      */
     get isNativeHostUnknown () {
         return this._connectionError === 'Specified native messaging host not found.';
     }
 
     /**
      * Adds incoming base64 encoded data to the existing response
      * @param {*} msg base64 encoded data.
      * @returns {Boolean}
      *
      * @private
      */
     collect (msg){
         if (typeof (msg) !== 'object' || !msg.hasOwnProperty('response')) {
             return gpgme_error('CONN_UNEXPECTED_ANSWER');
         }
         if (!this._response_b64){
             this._response_b64 = msg.response;
             return true;
         } else {
             this._response_b64 += msg.response;
             return true;
         }
     }
     /**
      * Decodes and verifies the base64 encoded answer data. Verified against
      * {@link permittedOperations}.
      * @returns {Object} The readable gpnupg answer
      */
     getMessage (){
         if (this._response_b64 === null){
             return gpgme_error('CONN_UNEXPECTED_ANSWER');
         }
         let _decodedResponse = JSON.parse(atob(this._response_b64));
         let _response = {
             format: 'ascii'
         };
         let messageKeys = Object.keys(_decodedResponse);
         let poa = permittedOperations[this.operation].answer;
         if (messageKeys.length === 0){
             return gpgme_error('CONN_UNEXPECTED_ANSWER');
         }
         for (let i= 0; i < messageKeys.length; i++){
             let key = messageKeys[i];
             switch (key) {
             case 'type': {
                 if (_decodedResponse.type === 'error'){
                     return (gpgme_error('GNUPG_ERROR',
                         decode(_decodedResponse.msg)));
                 } else if (poa.type.indexOf(_decodedResponse.type) < 0){
                     return gpgme_error('CONN_UNEXPECTED_ANSWER');
                 }
                 break;
             }
             case 'base64': {
                 break;
             }
             case 'msg': {
                 if (_decodedResponse.type === 'error'){
                     return (gpgme_error('GNUPG_ERROR', _decodedResponse.msg));
                 }
                 break;
             }
             default: {
                 let answerType = null;
                 if (poa.payload && poa.payload.hasOwnProperty(key)){
                     answerType = 'p';
                 } else if (poa.info && poa.info.hasOwnProperty(key)){
                     answerType = 'i';
                 }
                 if (answerType !== 'p' && answerType !== 'i'){
                     return gpgme_error('CONN_UNEXPECTED_ANSWER');
                 }
 
                 if (answerType === 'i') {
                     if ( typeof (_decodedResponse[key]) !== poa.info[key] ){
                         return gpgme_error('CONN_UNEXPECTED_ANSWER');
                     }
                     _response[key] = decode(_decodedResponse[key]);
 
                 } else if (answerType === 'p') {
                     if (_decodedResponse.base64 === true
                         && poa.payload[key] === 'string'
                     ) {
                         if (this.expected === 'uint8'){
                             _response[key] = atobArray(_decodedResponse[key]);
                             _response.format = 'uint8';
 
                         } else if (this.expected === 'base64'){
                             _response[key] = _decodedResponse[key];
                             _response.format = 'base64';
 
                         } else { // no 'expected'
                             _response[key] = Utf8ArrayToStr(
                                 atobArray(_decodedResponse[key]));
                             _response.format = 'string';
                         }
                     } else if (poa.payload[key] === 'string') {
                         _response[key] = _decodedResponse[key];
                     } else {
                         // fallthrough, should not be reached
                         // (payload is always string)
                         return gpgme_error('CONN_UNEXPECTED_ANSWER');
                     }
                 }
                 break;
             } }
         }
         return _response;
     }
 }