diff --git a/book/_addons/language_redirect.html b/book/_addons/language_redirect.html
index 9e8bfbc..0db37ab 100644
--- a/book/_addons/language_redirect.html
+++ b/book/_addons/language_redirect.html
@@ -7,7 +7,10 @@
       var userLang = navigator.language || navigator.userLanguage;
       var langPrefix = userLang.split("-")[0];
       var supportedLangs = ["en", "ko"];
-      var siteURL = window.location.href.split('/index.html')[0] + '/';
+      var siteURL = window.location.href.split('/index.html')[0];
+      if (!siteURL.endsWith('/')) {
+        siteURL += '/';
+      }
       var targetLang = supportedLangs.includes(langPrefix) ? langPrefix : "en";
       window.location.replace(siteURL + targetLang + "/index.html");
     </script>
@@ -16,3 +19,6 @@
     <p>Redirecting to the appropriate language...</p>
   </body>
 </html>
+
+  </body>
+</html>