diff --git a/stored-credentials/auth.js b/stored-credentials/auth.js
index e4ffda1d..a1ab6beb 100644
--- a/stored-credentials/auth.js
+++ b/stored-credentials/auth.js
@@ -1,3 +1,5 @@
+// Polyfill the "browser" global in Chrome.
+globalThis.browser ??= chrome;
 
 let target = "https://httpbin.org/basic-auth/*";
 
@@ -14,27 +16,27 @@ function completed(requestDetails) {
   }
 }
 
-function provideCredentialsAsync(requestDetails) {
-  // If we have seen this request before,
-  // then assume our credentials were bad,
+async function provideCredentialsAsync(requestDetails, asyncCallback) {
+  // If we have seen this request before, then assume our credentials were bad,
   // and give up.
   if (pendingRequests.indexOf(requestDetails.requestId) != -1) {
     console.log("bad credentials for: " + requestDetails.requestId);
     return {cancel: true};
-    
+
   } else {
     pendingRequests.push(requestDetails.requestId);
     console.log("providing credentials for: " + requestDetails.requestId);
-    // we can return a promise that will be resolved
-    // with the stored credentials
-    return browser.storage.local.get(null);
+    // We can respond asynchronously by calling asyncCallback and providing the
+    // authentication credentials.
+    const {authCredentials} = await browser.storage.local.get("authCredentials");
+    asyncCallback({authCredentials});
   }
 }
 
 browser.webRequest.onAuthRequired.addListener(
     provideCredentialsAsync,
     {urls: [target]},
-    ["blocking"]
+    ["asyncBlocking"]
   );
 
 browser.webRequest.onCompleted.addListener(
diff --git a/stored-credentials/manifest.json b/stored-credentials/manifest.json
index 65a15c8e..1429284a 100644
--- a/stored-credentials/manifest.json
+++ b/stored-credentials/manifest.json
@@ -1,6 +1,6 @@
 {
   "description": "Performs basic authentication by supplying stored credentials.",
-  "manifest_version": 2,
+  "manifest_version": 3,
   "name": "stored-credentials",
   "version": "2.0",
   "homepage_url": "https://github.com/mdn/webextensions-examples/tree/master/stored-credentials",
@@ -15,7 +15,8 @@
   },
 
   "background": {
-    "scripts": ["storage.js", "auth.js"]
+    "scripts": ["storage.js", "auth.js"],
+    "service_worker": "sw.js"
   },
 
   "options_ui": {
@@ -25,7 +26,11 @@
   "permissions": [
     "webRequest",
     "webRequestBlocking",
-    "storage",
+    "webRequestAuthProvider",
+    "storage"
+  ],
+
+  "host_permissions": [
     "https://httpbin.org/basic-auth/*"
   ]
 }
diff --git a/stored-credentials/options/options.js b/stored-credentials/options/options.js
index bb0477d6..80b7d64f 100644
--- a/stored-credentials/options/options.js
+++ b/stored-credentials/options/options.js
@@ -1,3 +1,6 @@
+// Polyfill the "browser" global in Chrome.
+globalThis.browser ??= chrome;
+
 const usernameInput = document.querySelector("#username");
 const passwordInput = document.querySelector("#password");
 
diff --git a/stored-credentials/storage.js b/stored-credentials/storage.js
index 847d1af4..c994332c 100644
--- a/stored-credentials/storage.js
+++ b/stored-credentials/storage.js
@@ -1,3 +1,6 @@
+// Polyfill the "browser" global in Chrome.
+globalThis.browser ??= chrome;
+
 /*
 Default settings. Initialize storage to these values.
 */
diff --git a/stored-credentials/sw.js b/stored-credentials/sw.js
new file mode 100644
index 00000000..fd40c51b
--- /dev/null
+++ b/stored-credentials/sw.js
@@ -0,0 +1,2 @@
+// Import and synchronously execute other JavaScript files.
+importScripts("storage.js", "auth.js");