diff --git a/source/js/post-helper.js b/source/js/post-helper.js
index 5a98f77..8e8b02a 100644
--- a/source/js/post-helper.js
+++ b/source/js/post-helper.js
@@ -92,7 +92,9 @@ function initToggleShowToc() {
     // watch comments count
     watchPostCommentsCount() {
       const commentsCountDom = this.postToolsDom.querySelector('.post-comments-count')
+      if (!commentsCountDom) return
       const config = { attributes: true, childList: true }
+
       const callback = function (mutationsList) {
         mutationsList.forEach((item) => {
           if (item.type === 'childList') {