diff --git a/source b/source
index 213f90acbef..20613699fe6 100644
--- a/source
+++ b/source
@@ -61957,8 +61957,9 @@ interface <dfn interface>HTMLDialogElement</dfn> : <span>HTMLElement</span> {
    <li><p>If <var>this</var> does not have an <code data-x="attr-dialog-open">open</code>
    attribute, then return.</p></li>
 
-   <li><p><span>Assert</span>: <var>this</var>'s <span data-x="dialog-close-watcher">close
-   watcher</span> is not null.</p></li>
+   <li><p>If <var>this</var>'s <span data-x="dialog-close-watcher">close watcher</span> is null,
+   then <span>close the dialog</span> <span>this</span> with <var>returnValue</var>, and
+   return.</p></li>
 
    <li><p>Set <var>dialog</var>'s <span>enable close watcher for <code
    data-x="dom-dialog-requestClose">requestClose()</code></span> to true.</p></li>