diff --git a/data/web/js/site/index.js b/data/web/js/site/index.js
index 4c812a37..29b72f0d 100644
--- a/data/web/js/site/index.js
+++ b/data/web/js/site/index.js
@@ -1,5 +1,6 @@
 $(document).ready(function() {
-  var theme = localStorage.getItem("theme");
-  localStorage.clear();
-  localStorage.setItem("theme", theme);
+  var theme = localStorage.getItem("mailcow_theme");
+  if (theme !== null) {
+    localStorage.setItem("mailcow_theme", theme);
+  }
 });
diff --git a/data/web/templates/base.twig b/data/web/templates/base.twig
index 4290edae..e1708950 100644
--- a/data/web/templates/base.twig
+++ b/data/web/templates/base.twig
@@ -11,8 +11,8 @@
   <link rel="stylesheet" href="{{ css_path }}">
   <script>
     // check if darkmode is preferred by OS or set by localStorage
-    if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches && localStorage.getItem("theme") !== "light" ||
-        localStorage.getItem("theme") === "dark") {
+    if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches && localStorage.getItem("mailcow_theme") !== "light" ||
+        localStorage.getItem("mailcow_theme") === "dark") {
       var head  = document.getElementsByTagName('head')[0];
       var link  = document.createElement('link');
       link.id   = 'dark-mode-theme';