diff --git a/spec/Overview.html b/spec/Overview.html
index 5a8000b..ba92f8a 100644
--- a/spec/Overview.html
+++ b/spec/Overview.html
@@ -8714,6 +8714,11 @@ <h4>Operations</h4>
             <dt>Derive Bits</dt>
             <dd>
               <ol>
+                <li>
+                  <p>
+                    If |length| is zero, then [= exception/throw =] an {{OperationError}}.
+                  </p>
+                </li>
                 <li>
                   <p>
                     If the {{CryptoKey/[[type]]}} internal slot of