diff --git a/assets/js/theme.js b/assets/js/theme.js
index 169ea21d41bd..f6c9cdf715a4 100644
--- a/assets/js/theme.js
+++ b/assets/js/theme.js
@@ -50,12 +50,13 @@ let transTheme = () => {
 
 
 let initTheme = (theme) => {
-  if (theme == null) {
+  if (theme == null || theme == 'null') {
     const userPref = window.matchMedia;
     if (userPref && userPref('(prefers-color-scheme: dark)').matches) {
         theme = 'dark';
     }
   }
+  
   setTheme(theme);
 }