diff --git a/app/Controllers/UpgradeController.php b/app/Controllers/UpgradeController.php
index 6e070aa..fad1161 100644
--- a/app/Controllers/UpgradeController.php
+++ b/app/Controllers/UpgradeController.php
@@ -2,24 +2,33 @@
 
 namespace App\Controllers;
 
+use App\Web\Session;
+use Monolog\Logger;
 use Psr\Http\Message\ResponseInterface as Response;
 use Psr\Http\Message\ServerRequestInterface as Request;
 use RuntimeException;
 use ZipArchive;
+use function glob_recursive;
+use function redirect;
+use function removeDirectory;
+use function route;
+use function urlFor;
 
 class UpgradeController extends Controller
 {
     const GITHUB_SOURCE_API = 'https://api.github.com/repos/SergiX44/XBackBone/releases';
 
     /**
-     * @param Response $response
+     * @param  Response  $response
      *
+     * @param  Logger  $logger
+     * @param  Session  $session
      * @return Response
      */
-    public function upgrade(Response $response): Response
+    public function upgrade(Response $response, Logger $logger, Session $session): Response
     {
         if (!is_writable(BASE_DIR)) {
-            $this->session->alert(lang('path_not_writable', BASE_DIR), 'warning');
+            $session->alert(lang('path_not_writable', BASE_DIR), 'warning');
 
             return redirect($response, route('system'));
         }
@@ -27,13 +36,13 @@ class UpgradeController extends Controller
         try {
             $json = $this->getApiJson();
         } catch (RuntimeException $e) {
-            $this->session->alert($e->getMessage(), 'danger');
+            $session->alert($e->getMessage(), 'danger');
 
             return redirect($response, route('system'));
         }
 
         if (version_compare($json[0]->tag_name, PLATFORM_VERSION, '<=')) {
-            $this->session->alert(lang('already_latest_version'), 'warning');
+            $session->alert(lang('already_latest_version'), 'warning');
 
             return redirect($response, route('system'));
         }
@@ -41,17 +50,17 @@ class UpgradeController extends Controller
         $tmpFile = sys_get_temp_dir().DIRECTORY_SEPARATOR.'xbackbone_update.zip';
 
         if (file_put_contents($tmpFile, file_get_contents($json[0]->assets[0]->browser_download_url)) === false) {
-            $this->session->alert(lang('cannot_retrieve_file'), 'danger');
+            $session->alert(lang('cannot_retrieve_file'), 'danger');
 
             return redirect($response, route('system'));
         }
 
         if (filesize($tmpFile) !== $json[0]->assets[0]->size) {
-            $this->session->alert(lang('file_size_no_match'), 'danger');
+            $session->alert(lang('file_size_no_match'), 'danger');
 
             return redirect($response, route('system'));
         }
-        $this->logger->info('System update started.');
+        $logger->info('System update started.');
 
         $config = require BASE_DIR.'config.php';
         $config['maintenance'] = true;
@@ -90,7 +99,7 @@ class UpgradeController extends Controller
         $updateZip->close();
         unlink($tmpFile);
 
-        $this->logger->info('System update completed.');
+        $logger->info('System update completed.');
 
         return redirect($response, urlFor('/install'));
     }
diff --git a/bootstrap/container.php b/bootstrap/container.php
index cb284f8..7a21e29 100644
--- a/bootstrap/container.php
+++ b/bootstrap/container.php
@@ -2,7 +2,6 @@
 
 use App\Database\DB;
 use App\Web\Lang;
-use App\Web\Session;
 use Aws\S3\S3Client;
 use function DI\factory;
 use function DI\get;
diff --git a/composer.lock b/composer.lock
index 3d0dd1d..6213006 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,20 +4,20 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "979e04cb72a48a50d7872132f8efa29f",
+    "content-hash": "6a0e292aa56135b799030a6b1e2152c0",
     "packages": [
         {
             "name": "aws/aws-sdk-php",
-            "version": "3.134.3",
+            "version": "3.134.5",
             "source": {
                 "type": "git",
                 "url": "https://github.com/aws/aws-sdk-php.git",
-                "reference": "3de2711a47e7c3f5e93a5c83f019188fd23f852f"
+                "reference": "f5a2d82660e73ed613643a5e7ad833d2569d5fdf"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/aws/aws-sdk-php/zipball/3de2711a47e7c3f5e93a5c83f019188fd23f852f",
-                "reference": "3de2711a47e7c3f5e93a5c83f019188fd23f852f",
+                "url": "https://api.github.com/repos/aws/aws-sdk-php/zipball/f5a2d82660e73ed613643a5e7ad833d2569d5fdf",
+                "reference": "f5a2d82660e73ed613643a5e7ad833d2569d5fdf",
                 "shasum": ""
             },
             "require": {
@@ -88,7 +88,7 @@
                 "s3",
                 "sdk"
             ],
-            "time": "2020-04-03T18:11:51+00:00"
+            "time": "2020-04-07T18:11:11+00:00"
         },
         {
             "name": "firebase/php-jwt",