diff --git a/src/danog/MadelineProto/Conversion.php b/src/danog/MadelineProto/Conversion.php
new file mode 100644
index 00000000..d18aebae
--- /dev/null
+++ b/src/danog/MadelineProto/Conversion.php
@@ -0,0 +1,81 @@
+<?php
+
+/*
+Copyright 2016-2018 Daniil Gentili
+(https://daniil.it)
+This file is part of MadelineProto.
+MadelineProto 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.
+MadelineProto 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 General Public License along with MadelineProto.
+If not, see <http://www.gnu.org/licenses/>.
+*/
+
+namespace danog\MadelineProto;
+
+class Conversion
+{
+    public static function telethon($session, $new_session, $settings = [])
+    {
+        set_error_handler(['\\danog\\MadelineProto\\Exception', 'ExceptionErrorHandler']);
+        if (!extension_loaded('sqlite3')) {
+            throw new Exception(['extension', 'sqlite3']);
+        }
+        if (!isset(pathinfo($session)['extension'])) {
+            $session .= '.session';
+        }
+        $session = Absolute::absolute($session);
+        $sqlite = new \PDO("sqlite:$session");
+        $sqlite->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_WARNING);
+
+        $sessions = $sqlite->query("SELECT * FROM sessions")->fetchAll();
+        $MadelineProto = new \danog\MadelineProto\API($new_session, $settings);
+        foreach ($sessions as $dc) {
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->auth_key = ['server_salt' => '', 'connection_inited' => true, 'id' => substr(sha1($dc['auth_key'], true), -8), 'auth_key' => $dc['auth_key']];
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->temp_auth_key = NULL;
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->ip = $dc['server_address'];
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->port = $dc['port'];
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->authorized = true;
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->session_id = $MadelineProto->random(8);
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->session_in_seq_no = 0;
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->session_out_seq_no = 0;
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->incoming_messages = [];
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->outgoing_messages = [];
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->new_outgoing = [];
+            $MadelineProto->API->datacenter->sockets[$dc['dc_id']]->incoming = [];
+        }
+        $MadelineProto->API->authorized = MTProto::LOGGED_IN;
+        $MadelineProto->API->init_authorization();
+        return $MadelineProto;
+    }
+
+    public static function pyrogram($session, $new_session, $settings = [])
+    {
+        set_error_handler(['\\danog\\MadelineProto\\Exception', 'ExceptionErrorHandler']);
+        if (!isset(pathinfo($session)['extension'])) {
+            $session .= '.session';
+        }
+        $session = Absolute::absolute($session);
+        $session = json_decode(file_get_contents($session), true);
+        $session['auth_key'] = base64_decode(implode('', $session['auth_key']));
+
+        $settings['connection_settings']['all']['test_mode'] = $session['test_mode'];
+
+        $MadelineProto = new \danog\MadelineProto\API($new_session, $settings);
+
+        $MadelineProto->API->datacenter->sockets[$session['dc_id']]->auth_key = ['server_salt' => '', 'connection_inited' => true, 'id' => substr(sha1($session['auth_key'], true), -8), 'auth_key' => $session['auth_key']];
+        $MadelineProto->API->datacenter->sockets[$session['dc_id']]->temp_auth_key = NULL;
+        $MadelineProto->API->datacenter->sockets[$session['dc_id']]->authorized = true;
+        $MadelineProto->API->datacenter->sockets[$session['dc_id']]->session_id = $MadelineProto->random(8);
+        $MadelineProto->API->datacenter->sockets[$session['dc_id']]->session_in_seq_no = 0;
+        $MadelineProto->API->datacenter->sockets[$session['dc_id']]->session_out_seq_no = 0;
+        $MadelineProto->API->datacenter->sockets[$session['dc_id']]->incoming_messages = [];
+        $MadelineProto->API->datacenter->sockets[$session['dc_id']]->outgoing_messages = [];
+        $MadelineProto->API->datacenter->sockets[$session['dc_id']]->new_outgoing = [];
+        $MadelineProto->API->datacenter->sockets[$session['dc_id']]->incoming = [];
+
+        $MadelineProto->API->authorized = MTProto::LOGGED_IN;
+        $MadelineProto->API->init_authorization();
+        return $MadelineProto;
+    }
+}
diff --git a/src/danog/MadelineProto/TL/Conversion/BotAPI.php b/src/danog/MadelineProto/TL/Conversion/BotAPI.php
index 0e8e2c77..7dd8b733 100644
--- a/src/danog/MadelineProto/TL/Conversion/BotAPI.php
+++ b/src/danog/MadelineProto/TL/Conversion/BotAPI.php
@@ -451,6 +451,9 @@ trait BotAPI
 
             $arguments['message'] = $this->html_fixtags($arguments['message']);
             $dom = new \DOMDocument();
+            if (!extension_loaded('mbstring')) {
+                throw new Exception(['extension', 'mbstring']);
+            }
             $dom->loadHTML(mb_convert_encoding($arguments['message'], 'HTML-ENTITIES', 'UTF-8'));
             if (!isset($arguments['entities'])) {
                 $arguments['entities'] = [];