diff --git a/web/install/bootstrap.php b/web/install/bootstrap.php
index 90e395c88..37c20e503 100644
--- a/web/install/bootstrap.php
+++ b/web/install/bootstrap.php
@@ -23,5 +23,5 @@
 define('THELIA_INSTALL_MODE', true);
 include __DIR__ . "/../../core/bootstrap.php";
 
-$thelia = new \Thelia\Core\Thelia("install", false);
+$thelia = new \Thelia\Core\Thelia("install", true);
 $thelia->boot();
\ No newline at end of file
diff --git a/web/install/header.php b/web/install/header.php
index 41c3d495e..b5db3ccd3 100644
--- a/web/install/header.php
+++ b/web/install/header.php
@@ -30,7 +30,7 @@ $lang = isset($_REQUEST['lang']) ? $_REQUEST['lang'] : null;
 if($lang){
     $_SESSION['install']['lang'] = $_REQUEST['lang'];
 }
-elseif(!$lang && !$_SESSION['install']['lang']){
+elseif(!$lang && !isset($_SESSION['install']['lang'])){
     $_SESSION['install']['lang'] = "en_US";
 }