diff --git a/composer.json b/composer.json
index aafbe7fbfb..f51dc21abf 100644
--- a/composer.json
+++ b/composer.json
@@ -22,7 +22,7 @@
         "jms/serializer"                   : "~0.10",
         "justinrainbow/json-schema"        : "~1.3",
         "mediavorus/mediavorus"            : "~0.4.0",
-        "media-alchemyst/media-alchemyst"  : "~0.3.1",
+        "media-alchemyst/media-alchemyst"  : "~0.4, >=0.4.3",
         "monolog/monolog"                  : "~1.3",
         "mrclay/minify"                    : "~2.1.6",
         "neutron/process-manager"          : "~1.0",
@@ -31,6 +31,7 @@
         "neutron/sphinxsearch-api"         : "~2.0.6",
         "neutron/recaptcha"                : "~0.1.0",
         "neutron/temporary-filesystem"     : "~2.1",
+        "php-ffmpeg/php-ffmpeg"            : "~0.4, >=0.4.3",
         "php-xpdf/php-xpdf"                : "~0.2.1",
         "phpexiftool/phpexiftool"          : "~0.3",
         "silex/silex"                      : "1.1.x-dev@dev",
diff --git a/composer.lock b/composer.lock
index 033f4cf230..e9acd51248 100644
--- a/composer.lock
+++ b/composer.lock
@@ -3,7 +3,7 @@
         "This file locks the dependencies of your project to a known state",
         "Read more about it at http://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file"
     ],
-    "hash": "daac732f5ff830bcaf81da6ecf16f9e2",
+    "hash": "c8348e356ce79bc133510a11279d48c9",
     "packages": [
         {
             "name": "alchemy-fr/tcpdf-clone",
@@ -1574,26 +1574,26 @@
         },
         {
             "name": "media-alchemyst/media-alchemyst",
-            "version": "0.3.6",
+            "version": "0.4.3",
             "source": {
                 "type": "git",
                 "url": "https://github.com/alchemy-fr/Media-Alchemyst.git",
-                "reference": "86a16aab82b6e31d2e70050f61fa815a98037253"
+                "reference": "319f55c2265a9056d68f1f0e6314dce977ef47ef"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/alchemy-fr/Media-Alchemyst/zipball/86a16aab82b6e31d2e70050f61fa815a98037253",
-                "reference": "86a16aab82b6e31d2e70050f61fa815a98037253",
+                "url": "https://api.github.com/repos/alchemy-fr/Media-Alchemyst/zipball/319f55c2265a9056d68f1f0e6314dce977ef47ef",
+                "reference": "319f55c2265a9056d68f1f0e6314dce977ef47ef",
                 "shasum": ""
             },
             "require": {
                 "alchemy/ghostscript": "~0.4.0",
                 "imagine/imagine": "0.6.x@dev",
-                "mediavorus/mediavorus": "~0.4.0",
+                "mediavorus/mediavorus": "~0.4.2",
                 "monolog/monolog": "~1.0",
                 "neutron/temporary-filesystem": "~2.1",
                 "php": ">=5.3.3",
-                "php-ffmpeg/php-ffmpeg": "~0.3, >=0.3.4",
+                "php-ffmpeg/php-ffmpeg": "~0.4.2",
                 "php-mp4box/php-mp4box": "~0.3.0",
                 "php-unoconv/php-unoconv": "~0.3.0",
                 "pimple/pimple": "~1.0",
@@ -1643,7 +1643,7 @@
                 "video",
                 "video processing"
             ],
-            "time": "2013-10-21 12:41:18"
+            "time": "2013-12-03 17:07:51"
         },
         {
             "name": "mediavorus/mediavorus",
diff --git a/lib/Alchemy/Phrasea/Core/Version.php b/lib/Alchemy/Phrasea/Core/Version.php
index a22a92e121..28af745b0f 100644
--- a/lib/Alchemy/Phrasea/Core/Version.php
+++ b/lib/Alchemy/Phrasea/Core/Version.php
@@ -15,6 +15,8 @@ class Version
 {
     protected static $number = '3.9.0-alpha.9';
     protected static $name = 'Epanterias';
+    protected static $number = '3.8.3-alpha.1';
+    protected static $name = 'Diplodocus';
 
     public static function getNumber()
     {
diff --git a/lib/Doctrine/Repositories/SessionRepository.php b/lib/Doctrine/Repositories/SessionRepository.php
new file mode 100644
index 0000000000..8e334961f5
--- /dev/null
+++ b/lib/Doctrine/Repositories/SessionRepository.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Repositories;
+
+use Doctrine\ORM\EntityRepository;
+
+/**
+ * SessionRepository
+ *
+ * This class was generated by the Doctrine ORM. Add your own custom
+ * repository methods below.
+ */
+class SessionRepository extends EntityRepository
+{
+    public function findByUser(\User_Adapter $user)
+    {
+        $dql = 'SELECT s
+            FROM Alchemy\Phrasea\Model\Entities\Session s
+            WHERE s.usr_id = :usr_id';
+
+        $query = $this->_em->createQuery($dql);
+        $query->setParameters(array('usr_id' => $user->get_id()));
+
+        return $query->getResult();
+    }
+}
diff --git a/lib/classes/User/Adapter.php b/lib/classes/User/Adapter.php
index 6581f0b729..8fbcebf4f6 100644
--- a/lib/classes/User/Adapter.php
+++ b/lib/classes/User/Adapter.php
@@ -751,6 +751,12 @@ class User_Adapter implements User_Interface, cache_cacheableInterface
             $this->app['EM']->remove($order);
         }
 
+        $repo = $this->app['EM']->getRepository('Alchemy\Phrasea\Model\Entities\Session');
+
+        foreach ($repo->findByUser($this) as $session) {
+            $this->app['EM']->remove($session);
+        }
+
         $this->app['EM']->flush();
 
         $sql = 'UPDATE usr SET usr_login = :usr_login , usr_mail = null
diff --git a/lib/classes/patch/383alpha1a.php b/lib/classes/patch/383alpha1a.php
new file mode 100644
index 0000000000..269e00c837
--- /dev/null
+++ b/lib/classes/patch/383alpha1a.php
@@ -0,0 +1,84 @@
+<?php
+
+/*
+ * This file is part of Phraseanet
+ *
+ * (c) 2005-2012 Alchemy
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+use Alchemy\Phrasea\Application;
+
+class patch_383alpha1a implements patchInterface
+{
+    /** @var string */
+    private $release = '3.8.3-alpha.1';
+
+    /** @var array */
+    private $concern = array(base::APPLICATION_BOX);
+
+    /**
+     * {@inheritdoc}
+     */
+    public function get_release()
+    {
+        return $this->release;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function require_all_upgrades()
+    {
+        return false;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getDoctrineMigrations()
+    {
+        return [];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function concern()
+    {
+        return $this->concern;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function apply(base $appbox, Application $app)
+    {
+        // Remove deleted users sessions
+        $sql = 'SELECT s.id FROM `Sessions` s, usr u WHERE u.usr_login LIKE "(#deleted%" AND u.usr_id = s.usr_id';
+        $stmt = $appbox->get_connection()->prepare($sql);
+        $stmt->execute();
+        $rows = $stmt->fetchAll(\PDO::FETCH_ASSOC);
+        $stmt->closeCursor();
+
+        foreach ($rows as $row) {
+            if (null !== $session = $app['EM']->find('Alchemy\Phrasea\Model\Entities\Session', $row['id'])) {
+                $app['EM']->remove($session);
+            }
+        }
+
+        // Remove API sessions
+        $query = $app['EM']->createQuery('SELECT s FROM Alchemy\Phrasea\Model\Entities\Session s WHERE s.user_agent LIKE :guzzle');
+        $query->setParameter(':guzzle', 'Guzzle%');
+
+        foreach ($query->getResult() as $session) {
+            $app['EM']->remove($session);
+        }
+
+        $app['EM']->flush();
+
+        return true;
+    }
+}
diff --git a/tests/classes/userTest.php b/tests/classes/userTest.php
index bb960af300..47cdd23336 100644
--- a/tests/classes/userTest.php
+++ b/tests/classes/userTest.php
@@ -49,6 +49,29 @@ class userTest extends PhraseanetPHPUnitAbstract
         $this->assertNull($repo->findWithProviderAndId('custom-one', 12345));
     }
 
+    public function testDeleteSetMailToNullAndRemovesSessions()
+    {
+        try {
+            $usrId = \User_Adapter::get_usr_id_from_login(self::$DI['app'], 'test_phpunit_sessions');
+            $user = \User_Adapter::getInstance($usrId, self::$DI['app']);
+        } catch (\Exception $e) {
+            $user = \User_Adapter::create(self::$DI['app'], 'test_phpunit_sessions', 'any', null, false);
+        }
+
+        $session = new \Alchemy\Phrasea\Model\Entities\Session();
+        $session
+            ->setUsrId($user->get_id())
+            ->setUserAgent('');
+
+        self::$DI['app']['EM']->persist($session);
+        self::$DI['app']['EM']->flush();
+
+        $user->delete();
+
+        $repo = self::$DI['app']['EM']->getRepository('Alchemy\Phrasea\Model\Entities\Session');
+        $this->assertCount(0, $repo->findByUser($user));
+    }
+
     public function testGetPref()
     {
         $user = $this->get_user();