diff --git a/app/views/layouts/main.php b/app/views/layouts/main.php
index cf38dfd..df69526 100644
--- a/app/views/layouts/main.php
+++ b/app/views/layouts/main.php
@@ -79,7 +79,7 @@ $navItems = [
     <?php endif; ?>
 
     <link rel="stylesheet" href="/fonts/fonts.css" />
-    <link rel="stylesheet" href="/css/haus-schleusingen.css" />
+    <link rel="stylesheet" href="/css/haus-schleusingen.css?v=<?= filemtime(__DIR__ . '/../../public/css/haus-schleusingen.css') ?>" />
     <?php if (isset($extraCss)): ?>
     <style><?= $extraCss ?></style>
     <?php endif; ?>