diff --git a/templates/base.html.twig b/templates/base.html.twig
index 9e01abdf..b6537c36 100644
--- a/templates/base.html.twig
+++ b/templates/base.html.twig
@@ -39,7 +39,7 @@
 
 
 
-        {% if theme %}
+        {% if theme and theme in constant('App\\Entity\\UserSystem\\User::AVAILABLE_THEMES') %}
             <link rel="stylesheet" href="{{ preload(asset('build/themes/' ~ theme ~ '.css'), {as: 'style'}) }}">
         {% else %}
             <link rel="stylesheet" href="{{ preload(asset('build/themes/bootstrap.css'), {as: 'style'}) }}">