diff --git a/templates/partials/doc/global_toc_script.html b/templates/partials/doc/global_toc_script.html
index 42abcda..8b23fec 100644
--- a/templates/partials/doc/global_toc_script.html
+++ b/templates/partials/doc/global_toc_script.html
@@ -16,8 +16,10 @@ document.addEventListener("DOMContentLoaded", function() {
     if (parentMenu.classList.contains('subMenu')) { // child
         parentMenu.previousElementSibling.previousElementSibling.checked = false;
     } else { // parent
-        activeDocPage.nextElementSibling.checked = false;
-    }  
+        if (activeDocPage.nextElementSibling) {
+            activeDocPage.nextElementSibling.checked = false;
+        }
+    }
 });
 
 window.addEventListener('scroll', function() {