diff --git a/plugins/kolab_2fa/composer.json b/plugins/kolab_2fa/composer.json
--- a/plugins/kolab_2fa/composer.json
+++ b/plugins/kolab_2fa/composer.json
@@ -21,8 +21,8 @@
     "require": {
         "php": ">=5.3.0",
         "roundcube/plugin-installer": ">=0.1.3",
-        "spomky-labs/otphp": "~5.0.0",
-        "endroid/qrcode": "~1.5.0",
+        "spomky-labs/otphp": "~6.0.0",
+        "endroid/qrcode": "~1.7.0",
         "enygma/yubikey": "~3.2"
     }
 }
diff --git a/plugins/kolab_2fa/kolab2fa.js b/plugins/kolab_2fa/kolab2fa.js
--- a/plugins/kolab_2fa/kolab2fa.js
+++ b/plugins/kolab_2fa/kolab2fa.js
@@ -274,7 +274,12 @@
     });
 
     // callback for save action
-    rcmail.addEventListener('plugin.save_success', function(data) {
+    rcmail.addEventListener('plugin.kolab_2fa_save_success', function(data) {
+        // force object
+        if (rcmail.env.kolab_2fa_factors.length !== undefined) {
+          rcmail.env.kolab_2fa_factors = {};
+        }
+
         if (!data.active && rcmail.env.kolab_2fa_factors[data.id]) {
             delete rcmail.env.kolab_2fa_factors[data.id];
         }
diff --git a/plugins/kolab_2fa/kolab_2fa.php b/plugins/kolab_2fa/kolab_2fa.php
--- a/plugins/kolab_2fa/kolab_2fa.php
+++ b/plugins/kolab_2fa/kolab_2fa.php
@@ -640,7 +640,7 @@
 
         if ($success) {
             $this->api->output->show_message($data === false ? $this->gettext('factorremovesuccess') : $this->gettext('factorsavesuccess'), 'confirmation');
-            $this->api->output->command('plugin.save_success', array('method' => $method, 'active' => $data !== false) + $save_data);
+            $this->api->output->command('plugin.kolab_2fa_save_success', array('id' => $method, 'active' => $data !== false) + $save_data);
         }
         else if ($errors) {
             $this->api->output->show_message($this->gettext('factorsaveerror'), 'error');
diff --git a/plugins/kolab_2fa/lib/Kolab2FA/Driver/HOTP.php b/plugins/kolab_2fa/lib/Kolab2FA/Driver/HOTP.php
--- a/plugins/kolab_2fa/lib/Kolab2FA/Driver/HOTP.php
+++ b/plugins/kolab_2fa/lib/Kolab2FA/Driver/HOTP.php
@@ -58,7 +58,7 @@
         );
 
         // copy config options
-        $this->backend = new \Kolab2FA\OTP\HOTP();
+        $this->backend = new \OTPHP\HOTP();
         $this->backend
             ->setDigits($this->config['digits'])
             ->setDigest($this->config['digest'])
diff --git a/plugins/kolab_2fa/lib/Kolab2FA/Driver/TOTP.php b/plugins/kolab_2fa/lib/Kolab2FA/Driver/TOTP.php
--- a/plugins/kolab_2fa/lib/Kolab2FA/Driver/TOTP.php
+++ b/plugins/kolab_2fa/lib/Kolab2FA/Driver/TOTP.php
@@ -52,7 +52,7 @@
         );
 
         // copy config options
-        $this->backend = new \Kolab2FA\OTP\TOTP();
+        $this->backend = new \OTPHP\TOTP();
         $this->backend
             ->setDigits($this->config['digits'])
             ->setInterval($this->config['interval'])
@@ -77,8 +77,8 @@
 
         $this->backend->setLabel($this->username)->setSecret($secret);
 
-        // PHP gets a string, but we're comparing integers.
-        $code = (int)$code;
+        // we're comparing strings
+        $code = strval($code);
 
         // Pass a window to indicate the maximum timeslip between client (mobile
         // device) and server.
diff --git a/plugins/kolab_2fa/lib/Kolab2FA/OTP/HOTP.php b/plugins/kolab_2fa/lib/Kolab2FA/OTP/HOTP.php
deleted file mode 100644
--- a/plugins/kolab_2fa/lib/Kolab2FA/OTP/HOTP.php
+++ /dev/null
@@ -1,58 +0,0 @@
-<?php
-
-/**
- * Kolab HOTP implementation based on Spomky-Labs/otphp
- *
- * This basically follows the exmaple implementation from
- * https://github.com/Spomky-Labs/otphp/tree/master/examples
- *
- * @author Thomas Bruederli <bruederli@kolabsys.com>
- *
- * Copyright (C) 2015, Kolab Systems AG <contact@kolabsys.com>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program 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 Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-
-namespace Kolab2FA\OTP;
-
-use OTPHP\HOTP as Base;
-
-class HOTP extends Base
-{
-    use OTP;
-    protected $counter = 0;
-
-    public function setCounter($counter)
-    {
-        if (!is_integer($counter) || $counter < 0) {
-            throw new \Exception('Counter must be at least 0.');
-        }
-        $this->counter = $counter;
-
-        return $this;
-    }
-
-    public function getCounter()
-    {
-        return $this->counter;
-    }
-
-    public function updateCounter($counter)
-    {
-        $this->counter = $counter;
-
-        return $this;
-    }
-}
\ No newline at end of file
diff --git a/plugins/kolab_2fa/lib/Kolab2FA/OTP/OTP.php b/plugins/kolab_2fa/lib/Kolab2FA/OTP/OTP.php
deleted file mode 100644
--- a/plugins/kolab_2fa/lib/Kolab2FA/OTP/OTP.php
+++ /dev/null
@@ -1,133 +0,0 @@
-<?php
-
-/**
- * Kolab OTP trait based on Spomky-Labs/otphp
- *
- * This basically follows the exmaple implementation from
- * https://github.com/Spomky-Labs/otphp/tree/master/examples
- *
- * @author Thomas Bruederli <bruederli@kolabsys.com>
- *
- * Copyright (C) 2015, Kolab Systems AG <contact@kolabsys.com>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program 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 Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-namespace Kolab2FA\OTP;
-
-trait OTP
-{
-    protected $secret = null;
-    protected $issuer = null;
-    protected $issuer_included_as_parameter = false;
-    protected $label = null;
-    protected $digest = 'sha1';
-    protected $digits = 6;
-
-    public function setSecret($secret)
-    {
-        $this->secret = $secret;
-
-        return $this;
-    }
-
-    public function getSecret()
-    {
-        return $this->secret;
-    }
-
-    public function setLabel($label)
-    {
-        if ($this->hasSemicolon($label)) {
-            throw new \Exception('Label must not contain a semi-colon.');
-        }
-        $this->label = $label;
-
-        return $this;
-    }
-
-    public function getLabel()
-    {
-        return $this->label;
-    }
-
-    public function setIssuer($issuer)
-    {
-        if ($this->hasSemicolon($issuer)) {
-            throw new \Exception('Issuer must not contain a semi-colon.');
-        }
-        $this->issuer = $issuer;
-
-        return $this;
-    }
-
-    public function getIssuer()
-    {
-        return $this->issuer;
-    }
-
-    public function isIssuerIncludedAsParameter()
-    {
-        return $this->issuer_included_as_parameter;
-    }
-
-    public function setIssuerIncludedAsParameter($issuer_included_as_parameter)
-    {
-        $this->issuer_included_as_parameter = $issuer_included_as_parameter;
-
-        return $this;
-    }
-
-    public function setDigits($digits)
-    {
-        if (!is_numeric($digits) || $digits < 1) {
-            throw new \Exception('Digits must be at least 1.');
-        }
-        $this->digits = $digits;
-
-        return $this;
-    }
-
-    public function getDigits()
-    {
-        return $this->digits;
-    }
-
-    public function setDigest($digest)
-    {
-        if (!in_array($digest, array('md5', 'sha1', 'sha256', 'sha512'))) {
-            throw new \Exception("'$digest' digest is not supported.");
-        }
-        $this->digest = $digest;
-
-        return $this;
-    }
-
-    public function getDigest()
-    {
-        return $this->digest;
-    }
-
-    private function hasSemicolon($value)
-    {
-        $semicolons = array(':', '%3A', '%3a');
-        foreach ($semicolons as $semicolon) {
-            if (false !== strpos($value, $semicolon)) {
-                return true;
-            }
-        }
-
-        return false;
-    }
-}
\ No newline at end of file
diff --git a/plugins/kolab_2fa/lib/Kolab2FA/OTP/TOTP.php b/plugins/kolab_2fa/lib/Kolab2FA/OTP/TOTP.php
deleted file mode 100644
--- a/plugins/kolab_2fa/lib/Kolab2FA/OTP/TOTP.php
+++ /dev/null
@@ -1,50 +0,0 @@
-<?php
-
-/**
- * Kolab TOTP implementation based on Spomky-Labs/otphp
- *
- * This basically follows the exmaple implementation from
- * https://github.com/Spomky-Labs/otphp/tree/master/examples
- *
- * @author Thomas Bruederli <bruederli@kolabsys.com>
- *
- * Copyright (C) 2015, Kolab Systems AG <contact@kolabsys.com>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program 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 Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-namespace Kolab2FA\OTP;
-
-use OTPHP\TOTP as Base;
-
-class TOTP extends Base
-{
-    use OTP;
-    protected $interval = 30;
-
-    public function setInterval($interval)
-    {
-        if (!is_integer($interval) || $interval < 1) {
-            throw new \Exception('Interval must be at least 1.');
-        }
-        $this->interval = $interval;
-
-        return $this;
-    }
-
-    public function getInterval()
-    {
-        return $this->interval;
-    }
-}
\ No newline at end of file