diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2e8a8dd..07c0b17 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## [v1.2.21](https://github.com/hibbitts-design/docsify-open-course-starter-kit/releases/tag/v1.2.21)
+### XX/XX/2024
+
+**Improved:**
+* Use of window.matchMedia.addListener replaced with window.matchMedia.addEventListener
+
 ## [v1.2.20](https://github.com/hibbitts-design/docsify-open-course-starter-kit/releases/tag/v1.2.20)
 ### 10/17/2024
 
diff --git a/docs/index.html b/docs/index.html
index 3fe764a..da1b4fa 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -272,7 +272,7 @@
                     embed.setAttribute('data-card-theme', 'light');
                   });
               }
-              window.matchMedia('(prefers-color-scheme: dark)').addListener(function (e) {
+              window.matchMedia('(prefers-color-scheme: dark)').addEventListener('change', function (e) {
                 // console.log(`changed to ${e.matches ? "dark" : "light"} mode`);
                 // console.log(e.matches);            
                 document.location.reload();