diff --git a/testing/web-platform/tests/web-bundle/resources/urn-uuid.har b/testing/web-platform/tests/web-bundle/resources/urn-uuid.har
index d821b768a60e..1708a8917b6c 100644
--- a/testing/web-platform/tests/web-bundle/resources/urn-uuid.har
+++ b/testing/web-platform/tests/web-bundle/resources/urn-uuid.har
@@ -35,7 +35,7 @@
             }
           ],
           "content": {
-            "text": "<script> window.parent.postMessage('subframe loaded from WBN: location = ' + location.href, '*'); </script>"
+            "text": "<script>\nwindow.addEventListener('message', (e) =>{e.source.postMessage(eval(e.data), e.origin);});\n</script>"
           }
         }
       }
diff --git a/testing/web-platform/tests/web-bundle/resources/wbn/urn-uuid.wbn b/testing/web-platform/tests/web-bundle/resources/wbn/urn-uuid.wbn
index 45db6fefbbe0..3255787c1c57 100644
Binary files a/testing/web-platform/tests/web-bundle/resources/wbn/urn-uuid.wbn and b/testing/web-platform/tests/web-bundle/resources/wbn/urn-uuid.wbn differ
diff --git a/testing/web-platform/tests/web-bundle/subresource-loading/subframe-from-web-bundle.tentative.html b/testing/web-platform/tests/web-bundle/subresource-loading/subframe-from-web-bundle.tentative.html
index 1e5cdd6943eb..f6f2b769d0f1 100644
--- a/testing/web-platform/tests/web-bundle/subresource-loading/subframe-from-web-bundle.tentative.html
+++ b/testing/web-platform/tests/web-bundle/subresource-loading/subframe-from-web-bundle.tentative.html
@@ -9,27 +9,98 @@
 <body>
 <script>
 
-promise_test(async () => {
-  const frame_url = 'urn:uuid:429fcc4e-0696-4bad-b099-ee9175f023ae';
-  const link = document.createElement('link');
-  link.rel = 'webbundle';
-  link.href = '../resources/wbn/urn-uuid.wbn';
-  link.resources = frame_url;
-  document.body.appendChild(link);
-  const message_promisse = new Promise((resolve) => {
-      window.addEventListener('message', (e) => {
-          resolve(e.data);
-      });
-    });
-  const iframe = document.createElement('iframe');
-  iframe.src = frame_url;
-  document.body.appendChild(iframe);
-  assert_equals(
-      await message_promisse,
-      'subframe loaded from WBN: location = ' + frame_url);
-  document.body.removeChild(link);
-  document.body.removeChild(iframe);
-}, "Subframe load from Web Bundle");
+const frame_url = 'urn:uuid:429fcc4e-0696-4bad-b099-ee9175f023ae';
 
+urn_uuid_iframe_test(
+  'location.href',
+  frame_url,
+  'location.href in urn uuid iframe.');
+
+urn_uuid_iframe_test(
+  '(' + (() => {
+    try {
+      let result = window.localStorage;
+      return 'no error';
+    } catch (e) {
+      return e.name;
+    }
+  }).toString() + ')()',
+  'SecurityError',
+  'Accesing window.localStorage should throw a SecurityError.');
+
+urn_uuid_iframe_test(
+  '(' + (() => {
+    try {
+      let result = window.sessionStorage;
+      return 'no error';
+    } catch (e) {
+      return e.name;
+    }
+  }).toString() + ')()',
+  'SecurityError',
+  'Accesing window.sessionStorage should throw a SecurityError.');
+
+urn_uuid_iframe_test(
+  '(' + (() => {
+    try {
+      let result = document.cookie;
+      return 'no error';
+    } catch (e) {
+      return e.name;
+    }
+  }).toString() + ')()',
+  'SecurityError',
+  'Accesing document.cookie should throw a SecurityError.');
+
+urn_uuid_iframe_test(
+  '(' + (() => {
+    try {
+      let request = window.indexedDB.open("db");
+      return 'no error';
+    } catch (e) {
+      return e.name;
+    }
+  }).toString() + ')()',
+  'SecurityError',
+  'Opening an indexedDB should throw a SecurityError.');
+
+urn_uuid_iframe_test(
+  'window.caches === undefined',
+  true,
+  'window.caches should be undefined.');
+
+function urn_uuid_iframe_test(code, expected, name) {
+  promise_test(async () => {
+    const link = document.createElement('link');
+    link.rel = 'webbundle';
+    link.href = '../resources/wbn/urn-uuid.wbn';
+    link.resources = frame_url;
+    document.body.appendChild(link);
+    const iframe = document.createElement('iframe');
+    iframe.src = frame_url;
+    const load_promise = new Promise((resolve) => {
+      iframe.addEventListener('load', resolve);
+    });
+    document.body.appendChild(iframe);
+    await load_promise;
+    assert_equals(
+        await evalInIframe(iframe, code),
+        expected);
+    document.body.removeChild(link);
+    document.body.removeChild(iframe);
+  }, name);
+}
+
+async function evalInIframe(iframe, code) {
+  const message_promise = new Promise((resolve) => {
+      const listener = (e) => {
+        window.removeEventListener('message', listener);
+        resolve(e.data);
+      }
+      window.addEventListener('message', listener);
+    });
+  iframe.contentWindow.postMessage(code,'*');
+  return message_promise;
+}
 </script>
 </body>
