diff --git a/_config.yml b/_config.yml
index a4d3a91..cb8926c 100644
--- a/_config.yml
+++ b/_config.yml
@@ -176,7 +176,7 @@ footer-hover-col: "#0085A1"
 #  uri: "demo.wiki.pro"
 #  opt-out: true
 
-# Gogle Universal Analytics ID -- deprecated
+# Google Universal Analytics ID -- deprecated
 # As of July 2023 this is no longer supported by Google! If you are still using `google_analytics`,
 # you should switch to using the `gtag` field above instead.
 #google_analytics: "UA-XXXXXXXX-X"
diff --git a/_includes/google_analytics.html b/_includes/google_analytics.html
index 01f7406..d9b053f 100644
--- a/_includes/google_analytics.html
+++ b/_includes/google_analytics.html
@@ -1,5 +1,17 @@
 {% if site.google_analytics %}
 <!-- Google Analytics -->
+{% unless site.gtag %}
+<div id="bj-ganalytics-deprecated-msg" style="position: fixed; background: #b90404; bottom: 0; width: 100%; z-index: 10000; color: #f0f0f0; text-align: center;">
+  <div title="Close" onclick="$(this).parent().remove()" style="position: absolute; right: 5px; top: 0; font-size: 1.5em; line-height: 1; cursor: pointer;">&times;</div>
+  <div style="max-width: 800px; margin: auto; font-size: 1.1em">
+    This website is using outdated Google Analytics
+    <details style="font-size: 0.8em; margin-bottom: 5px;">
+      <summary>More info</summary>
+      As of July 2023, Google's Universal Analytics is going away and being replaced by Google Analytics 4. This website is still using the old Universal Analytics. In order to remove this message, the website owner must remove the <code>google_analytics</code> property in the website's config file, and optionally replace it with the new <code>gtag</code> property.
+    </details>
+  </div>
+</div>
+{% endunless %}
 <script>
   (function (i, s, o, g, r, a, m) {
     i['GoogleAnalyticsObject'] = r; i[r] = i[r] || function () {