diff --git a/spec/Overview.html b/spec/Overview.html
index 6378561..2c6c0ba 100644
--- a/spec/Overview.html
+++ b/spec/Overview.html
@@ -14391,6 +14391,12 @@ <h4>Operations</h4>
                     |algorithm| to "`HMAC`".
                   </p>
                 </li>
+                <li>
+                  <p>
+                    Set the {{HmacKeyAlgorithm/length}} attribute of
+                    |algorithm| to |length|.
+                  </p>
+                </li>
                 <li>
                   <p>
                     Let |hash| be a new