diff --git a/config/staging/fileload.php b/config/staging/fileload.php
index 0132667..cb45699 100644
--- a/config/staging/fileload.php
+++ b/config/staging/fileload.php
@@ -28,6 +28,15 @@ if (php_sapi_name() !== 'cli') {
 // 1) Sprache bestimmen (vor dem Laden der JSON-Dateien!)
 // -----------------------------------------------------------
 $lang = $_GET['lang'] ?? null;
+
+if (is_string($lang)) {
+    $lang = strtolower($lang);
+    if (!preg_match('/^[a-z]{2}$/', $lang)) {
+        $lang = null;
+    }
+} else {
+    $lang = null;
+}
 $lang = strtolower($lang);
 
 if (!preg_match('/^[a-z]{2}$/', $lang)) {