diff --git a/docs/website/index.html b/docs/website/index.html
index bb1d00a..ad924ef 100644
--- a/docs/website/index.html
+++ b/docs/website/index.html
@@ -120,6 +120,13 @@ <h1>History</h1>
 
     <dl>
 
+        <dt>2022-03-22</dt>
+        <dd>Version 9.1 released. Changes:
+            <ul>
+                <li>Added the <code>-p</code> command line option for setting the prelude.</li>
+            </ul>
+        </dd>
+
         <dt>2022-02-16</dt>
         <dd>Version 9.0 released. Changes:
             <ul>