diff --git a/reference/mysqlnd/notes.xml b/reference/mysqlnd/notes.xml
index fc879ca934a0..33c8b83fc0d4 100644
--- a/reference/mysqlnd/notes.xml
+++ b/reference/mysqlnd/notes.xml
@@ -12,6 +12,11 @@
    streams documentation (<xref linkend="book.stream"/>) should be consulted
    on such details as timeout settings, not the documentation for the MySQL
    Client Library.</simpara></listitem>
+   <listitem><simpara>As of PHP 8.4.0, when connecting to a MySQL server of
+   version 8.0.24 or later, the error code reported for a server wait timeout
+   is <literal>4031</literal>
+   (<literal>ER_CLIENT_INTERACTION_TIMEOUT</literal>) instead of
+   <literal>2006</literal> (<literal>CR_SERVER_GONE_ERROR</literal>).</simpara></listitem>
  </itemizedlist>
 </chapter>
 <!-- Keep this comment at the end of the file