diff --git a/index.html b/index.html
index 89e683c..cde43a9 100644
--- a/index.html
+++ b/index.html
@@ -376,6 +376,7 @@ <h3>
               readonly attribute unsigned short responseStatus;
               readonly attribute RenderBlockingStatusType renderBlockingStatus;
               readonly attribute DOMString contentType;
+              readonly attribute DOMString contentEncoding;
               [Default] object toJSON();
           };
         </pre>
@@ -715,6 +716,13 @@ <h3>
           <a data-for="PerformanceResourceTiming">resource info</a>'s
           [=response body info/content type=].
         </p>
+        <p data-dfn-for="PerformanceResourceTiming">
+          The <dfn>contentEncoding</dfn> getter steps are to return a filtered
+          value of <a>this</a>'s <a data-for="PerformanceResourceTiming">
+          resource info</a>'s [=response body info/content encoding=]. If the
+          value is not an empty string and it's not an encoding value the
+          browser natively supports, return `unknown` instead.
+        </p>
         <p data-dfn-for="PerformanceResourceTiming">
           The <dfn>renderBlockingStatus</dfn> getter steps are to return
           <a data-link-for="RenderBlockingStatusType">blocking</a> if