diff --git a/_includes/upgrade-notice.html b/_includes/upgrade-notice.html
--- a/_includes/upgrade-notice.html
+++ b/_includes/upgrade-notice.html
@@ -19,6 +19,10 @@
 
 <div id="upgrade-notice-pre-activation" class="hero-box" style="background: #ffe090; display: none;">
   <h3>Prepare for the May 2021 upgrade today!</h3>
+  On May 15th, 2021, the Bitcoin ABC network will upgrade.
+  When the median time of the last 11 blocks is over timestamp 1621080000 (12:00:00 UTC),
+  the nodes running a version prior 0.23.0 will no longer be in sync with the BCHA network.
+  <br />
   In order to keep running after May 15th, 2021, your node needs to
   be updated to version 0.23.0 or later.<br />
   Update early to keep your node in sync with the BCHA network !
diff --git a/bcha.html b/bcha.html
--- a/bcha.html
+++ b/bcha.html
@@ -6,6 +6,7 @@
 
 <div class="flex-content">
   <div id="bchapage">
+    {% include upgrade-notice.html %}
     <div class="bcha-section">
       <h1>BCHA: quick guide</h1>
       <p>Want to know more about BCHA? We’ve got you covered!</p>
diff --git a/index.html b/index.html
--- a/index.html
+++ b/index.html
@@ -17,6 +17,8 @@
 
   <hr />
 
+  {% include upgrade-notice.html %}
+
   {% assign latestVersion = site.data.github-releases[0].name %}
   <h2><a href="/releases/">Install the latest version ({{ latestVersion }})</a></h2>