diff --git a/source b/source
index f1ceb847a67..f81db80abcf 100644
--- a/source
+++ b/source
@@ -53722,8 +53722,8 @@ interface <dfn interface>HTMLButtonElement</dfn> : <span>HTMLElement</span> {
       <code>CommandEvent</code>, with its <code data-x="dom-CommandEvent-command">command</code>
       attribute initialized to <var>command</var>, its <code
       data-x="dom-CommandEvent-source">source</code> attribute initialized to <var>element</var>,
-      and its <code data-x="dom-Event-cancelable">cancelable</code> and <code
-      data-x="dom-Event-composed">composed</code> attributes initialized to true.</p>
+      and its <code data-x="dom-Event-cancelable">cancelable</code> attribute initialized to
+      true.</p>
 
       <p class="XXX"><a href="https://github.com/whatwg/dom/issues/1328">DOM standard issue
       #1328</a> tracks how to better standardize associated event data in a way which makes sense on