diff --git a/lib/classes/patch/383alpha4a.php b/lib/classes/patch/383alpha4a.php
new file mode 100644
index 0000000000..c3802d5818
--- /dev/null
+++ b/lib/classes/patch/383alpha4a.php
@@ -0,0 +1,97 @@
+<?php
+
+/*
+ * This file is part of Phraseanet
+ *
+ * (c) 2005-2014 Alchemy
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+use Alchemy\Phrasea\Application;
+use Doctrine\ORM\Query\ResultSetMapping;
+
+class patch_383alpha4a implements patchInterface
+{
+    /** @var string */
+    private $release = '3.8.3-alpha.4';
+
+    /** @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 concern()
+    {
+        return $this->concern;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function apply(base $appbox, Application $app)
+    {
+        $em = $app['EM'];
+        $mappingFieldType = $mappingFieldResult = new ResultSetMapping();
+
+        $rs = $em->createNativeQuery(
+            "SHOW FIELDS FROM usr WHERE Field = 'usr_login';",
+            $mappingFieldType->addScalarResult('Type', 'Type')
+        )->getSingleResult();
+
+        if (0 !== strpos(strtolower($rs['Type']), 'varbinary')) {
+            return;
+        }
+
+        // As 'usr_login' field type is varbinary it can contain any charset (utf8 or latin1).
+        // Compare usr_login to usr_login converted to utf8>utf32>utf8
+        // will detect broken char for latin1 encoded string.
+        // Then detected 'usr_login' fields  must be converted from latin1 to utf8.
+        $rs = $em->createNativeQuery(
+            'SELECT t.usr_id, t.login_utf8 FROM (
+                SELECT usr_id,
+                usr_login AS login_unknown_charset,
+                CONVERT(CAST(usr_login AS CHAR CHARACTER SET latin1) USING utf8) AS login_utf8,
+                CONVERT(CONVERT(CAST(usr_login AS CHAR CHARACTER SET utf8) USING utf32) USING utf8) AS login_utf8_utf32_utf8
+                FROM usr
+            ) AS t
+            WHERE t.login_utf8_utf32_utf8 != t.login_unknown_charset',
+            $mappingFieldResult->addScalarResult('usr_id', 'usr_id')->addScalarResult('login_utf8', 'login_utf8')
+        )->getResult();
+
+        foreach ($rs as $row) {
+            $em->getConnection()->executeQuery(sprintf('UPDATE usr SET usr_login="%s" WHERE usr_id=%d', $row['login_utf8'], $row['usr_id']));
+        }
+
+        foreach (array(
+                     // drop index
+                     "ALTER TABLE usr DROP INDEX usr_login;",
+                     // change field type
+                     "ALTER TABLE usr MODIFY usr_login VARCHAR(128) CHARACTER SET utf8 COLLATE utf8_bin;",
+                     // recreate index
+                     "CREATE UNIQUE INDEX usr_login ON usr (usr_login);"
+                 ) as $sql) {
+            $em->getConnection()->executeQuery($sql);
+        }
+
+        return true;
+    }
+}