diff --git a/public/index.php b/public/index.php
index 35648df..ea3850c 100644
--- a/public/index.php
+++ b/public/index.php
@@ -38,6 +38,7 @@ foreach (MDEventsSet::EVENT_IDS as $j) {
 $availableLangs = MD_STD::scandir(__DIR__ . "/../l10n/translation-musdb");
 
 if (!empty($_GET['id']) and !($id = filter_var($_GET['id'], FILTER_VALIDATE_INT))) {
+    http_response_code(404);
     echo "Error: IDs must be presented in a numeric format.";
     return;
 }