diff --git a/src/service-worker.ts b/src/service-worker.ts
index 75c64997..6af3be77 100644
--- a/src/service-worker.ts
+++ b/src/service-worker.ts
@@ -1,3 +1,6 @@
+// SPDX-License-Identifier: MIT
+// Copyright (c) 2022 The Pybricks Authors
+
 /// <reference lib="webworker" />
 /* eslint-disable no-restricted-globals */
 
@@ -11,10 +14,9 @@
 // istanbul ignore file
 
 import { clientsClaim } from 'workbox-core';
-import { ExpirationPlugin } from 'workbox-expiration';
 import { createHandlerBoundToURL, precacheAndRoute } from 'workbox-precaching';
 import { registerRoute } from 'workbox-routing';
-import { StaleWhileRevalidate } from 'workbox-strategies';
+import { CacheFirst } from 'workbox-strategies';
 
 declare const self: ServiceWorkerGlobalScope;
 
@@ -59,15 +61,10 @@ registerRoute(
 // precache, in this case same-origin .png requests like those from in public/
 registerRoute(
     // Add in any other file extensions or routing criteria as needed.
-    ({ url }) => url.origin === self.location.origin && url.pathname.endsWith('.png'),
+    ({ request }) => request.destination === 'image',
     // Customize this strategy as needed, e.g., by changing to CacheFirst.
-    new StaleWhileRevalidate({
+    new CacheFirst({
         cacheName: 'images',
-        plugins: [
-            // Ensure that once this runtime cache reaches a maximum size the
-            // least-recently used images are removed.
-            new ExpirationPlugin({ maxEntries: 50 }),
-        ],
     }),
 );