diff --git a/index.php b/index.php
index 43eaa96..6e23a31 100644
--- a/index.php
+++ b/index.php
@@ -64,7 +64,7 @@
         // Informations for user
         if ($_SERVER['REQUEST_METHOD'] === 'GET')
         {
-                if ($_GET['id'])
+                if (isset($_GET['id']))
                 {
                         if (is_dir(_DATA_DIR . "/" . $_GET['id']))
                         {