diff --git a/source b/source
index 32bc1ef0b30..ab2304e2169 100644
--- a/source
+++ b/source
@@ -3771,6 +3771,7 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li><dfn data-x-href="https://w3c.github.io/ServiceWorker/#serviceworker"><code>ServiceWorker</code></dfn> interface</li>
      <li><dfn data-x-href="https://w3c.github.io/ServiceWorker/#serviceworkercontainer"><code>ServiceWorkerContainer</code></dfn> interface</li>
      <li><dfn data-x-href="https://w3c.github.io/ServiceWorker/#dfn-update-via-cache">update via cache mode</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/ServiceWorker/#enumdef-serviceworkerupdateviacache">ServiceWorkerUpdateViaCache</dfn> enumeration</li>
     </ul>
 
    </dd>
@@ -12847,7 +12848,7 @@ interface <dfn>HTMLLinkElement</dfn> : <span>HTMLElement</span> {
   [<span>CEReactions</span>] attribute DOMString <span data-x="dom-link-referrerPolicy">referrerPolicy</span>;
   [<span>CEReactions</span>] attribute USVString <span data-x="dom-link-scope">scope</span>;
   [<span>CEReactions</span>] attribute <span>WorkerType</span> <span data-x="dom-link-workertype">workerType</span>;
-  [<span>CEReactions</span>] attribute boolean <span data-x="dom-link-updateViaCache">updateViaCache</span>;
+  [<span>CEReactions</span>] attribute <span>ServiceWorkerUpdateViaCache</span> updateViaCache;
 };
 <span>HTMLLinkElement</span> implements <span>LinkStyle</span>;</pre>
    </dd>
@@ -13040,9 +13041,12 @@ interface <dfn>HTMLLinkElement</dfn> : <span>HTMLElement</span> {
 
   <p>The <dfn><code data-x="attr-link-updateviacache">updateviacache</code></dfn> attribute is an
   <span>enumerated attribute</span> that specifies the <span>update via cache mode</span> for a
-  <span>service worker registration</span>. The attribute must not be specified on <code>link</code>
-  elements that do not have a <code data-x="attr-link-rel">rel</code> attribute that contains the
-  <code data-x="rel-serviceworker">serviceworker</code> keyword.</p>
+  <span>service worker registration</span>. The attribute's keywords are
+  "<code data-x="">imports</code>", "<code data-x="">all</code>", and "<code data-x="">never</code>,
+  which map to the respective states <i>imports</i>, <i>all</i>, and <i>never</i>. The <span>missing
+  value default</span> is the <i>imports</i> state. The attribute must not be specified on
+  <code>link</code> elements that do not have a <code data-x="attr-link-rel">rel</code> attribute
+  that contains the <code data-x="rel-serviceworker">serviceworker</code> keyword.</p>
 
   <p>The <dfn><code data-x="attr-link-workertype">workertype</code></dfn> attribute is an
   <span>enumerated attribute</span> that specifies the <span>service worker type</span> for a