diff --git a/source/js/dark-light-toggle.js b/source/js/dark-light-toggle.js
index 398bfcb..ee7c494 100644
--- a/source/js/dark-light-toggle.js
+++ b/source/js/dark-light-toggle.js
@@ -56,7 +56,7 @@ window.addEventListener('DOMContentLoaded', () => {
     },
 
     initModeToggleButton() {
-      this.modeToggleButton_dom.addEventListener('click', () => {
+      this.modeToggleButton_dom && this.modeToggleButton_dom.addEventListener('click', () => {
         if (window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches) {
           this.setItemUtil('light-mode', 'dark');
         } else {
diff --git a/source/js/utils.js b/source/js/utils.js
index ca902c7..8ffa9cf 100644
--- a/source/js/utils.js
+++ b/source/js/utils.js
@@ -72,7 +72,7 @@ ILS.utils = {
     this.toolsMenuButton_dom = document.querySelector('.tools-button');
     this.toolsWrapperList_dom = document.querySelectorAll('.tools-wrapper li');
 
-    this.toolsMenuButton_dom.addEventListener('click', e => {
+    this.toolsMenuButton_dom && this.toolsMenuButton_dom.addEventListener('click', e => {
       isOpen = !isOpen;
 
       const toolsMenuButtonIcon = this.toolsMenuButton_dom.querySelector('i');