diff --git a/source b/source
index 12e2cc25786..1b8f750af34 100644
--- a/source
+++ b/source
@@ -118587,8 +118587,8 @@ interface <dfn interface>MessageChannel</dfn> {
     <thead>
      <tr><th><span data-x="event handlers">Event handler</span> <th><span>Event handler event type</span>
     <tbody>
-     <tr><td><dfn attribute for="MessageEventTarget"><code data-x="handler-MessageEventTarget-onmessage">onmessage</code></dfn> <td> <code data-x="event-message">message</code>
-     <tr><td><dfn attribute for="MessageEventTarget"><code data-x="handler-MessageEventTarget-onmessageerror">onmessageerror</code></dfn> <td> <code data-x="event-messageerror">messageerror</code>
+     <tr><td><span id="handler-messageport-onmessage"></span><span id="handler-worker-onmessage"></span><span id="handler-dedicatedworkerglobalscope-onmessage"></span><dfn attribute for="MessageEventTarget"><code data-x="handler-MessageEventTarget-onmessage">onmessage</code></dfn> <td> <code data-x="event-message">message</code>
+     <tr><td><span id="handler-messageport-onmessageerror"></span><span id="handler-worker-onmessageerror"></span><span id="handler-dedicatedworkerglobalscope-onmessageerror"></span><dfn attribute for="MessageEventTarget"><code data-x="handler-MessageEventTarget-onmessageerror">onmessageerror</code></dfn> <td> <code data-x="event-messageerror">messageerror</code>
    </table>
 
   <h4>Message ports</h4>