diff --git a/layouts/partials/toc.html b/layouts/partials/toc.html
index 959347ac..35393cdd 100644
--- a/layouts/partials/toc.html
+++ b/layouts/partials/toc.html
@@ -33,11 +33,16 @@
 
     function getActiveAnchorId(anchors, offsetRatio) {
       const threshold = window.scrollY + window.innerHeight * offsetRatio
+      const tocLinks = [...document.querySelectorAll('#TableOfContents a[href^="#"]')]
+      const tocIds = new Set(tocLinks.map(link => link.getAttribute('href').substring(1)))
+      
       for (let i = anchors.length - 1; i >= 0; i--) {
         const top = anchors[i].getBoundingClientRect().top + window.scrollY
-        if (top <= threshold) return anchors[i].id
+        if (top <= threshold && tocIds.has(anchors[i].id)) {
+          return anchors[i].id
+        }
       }
-      return anchors[0]?.id || ''
+      return anchors.find(anchor => tocIds.has(anchor.id))?.id || ''
     }
 
     function updateTOC({ toc, anchors, links, scrollOffset, collapseInactive }) {