diff --git a/index.html b/index.html
index 38ec31b..0cbc050 100644
--- a/index.html
+++ b/index.html
@@ -653,7 +653,7 @@ <h2>Overview of Service-Worker-Based Approach</h2>
         is necessary, the <a>payment app</a> can open a <a>payment app
         window</a> for that purpose.</li>
     <li>Finally, once the <a>payment app</a> is finished with its processing, it
-        resolves a <a>promise</a> passed to it in the event. This causes the
+        resolves a <a>Promise</a> passed to it in the event. This causes the
         <code>Promise&lt;PaymentResponse&gt;</code> returned from
         <code>PaymentRequest.show()</code> to resolve.</li>
   </ol>