diff --git a/templates/_footer_lang.html b/templates/_footer_lang.html
index 5eafc9f..25701af 100644
--- a/templates/_footer_lang.html
+++ b/templates/_footer_lang.html
@@ -1,6 +1,6 @@
 <div class="footer-lang">
   <label for="lang-select" class="sr-only">{{ t_language }}</label>
-  <select id="lang-select" class="lang-select" autocomplete="off" onchange="if(this.value){var u=new URL(this.value,window.location.origin);u.search=window.location.search;window.location.href=u.href}">
+  <select id="lang-select" class="lang-select" autocomplete="off" onchange="if(this.value){var u=new(window.URL)(this.value,window.location.origin);u.search=window.location.search;window.location.href=u.href}">
     {% for l in all_locales %}
     <option value="/{{ l.tag() }}"{% if *l == locale %} selected{% endif %}>{{ l.name() }}</option>
     {% endfor %}