diff --git a/testing/web-platform/meta/MANIFEST.json b/testing/web-platform/meta/MANIFEST.json
index b0b282e714ea..a7eaaf98d530 100644
--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -591322,7 +591322,7 @@
    "support"
   ],
   "interfaces/picture-in-picture.idl": [
-   "3e97112286c64d274a4ecbdb0f41d4700e5448fb",
+   "4051a7f0ba28e984294ca32a5a2aef73b7f9a6bb",
    "support"
   ],
   "interfaces/pointerevents-extension.idl": [
@@ -602154,7 +602154,7 @@
    "testharness"
   ],
   "picture-in-picture/idlharness.window.js": [
-   "4b24a93a59e290c762969a4f8c33e24ebe37bf9b",
+   "0fecf6b24a57f6ae7ca605782fdd9bc66e3fa562",
    "testharness"
   ],
   "picture-in-picture/leave-picture-in-picture.html": [
diff --git a/testing/web-platform/tests/interfaces/picture-in-picture.idl b/testing/web-platform/tests/interfaces/picture-in-picture.idl
index e15515d0e7f9..cafcae11df77 100644
--- a/testing/web-platform/tests/interfaces/picture-in-picture.idl
+++ b/testing/web-platform/tests/interfaces/picture-in-picture.idl
@@ -4,19 +4,18 @@
 // See: https://wicg.github.io/picture-in-picture/
 
 partial interface HTMLVideoElement {
-  Promise<PictureInPictureWindow> requestPictureInPicture();
+  [NewObject] Promise<PictureInPictureWindow> requestPictureInPicture();
 
   attribute EventHandler onenterpictureinpicture;
   attribute EventHandler onleavepictureinpicture;
 
-  [CEReactions]
-  attribute boolean disablePictureInPicture;
+  [CEReactions] attribute boolean disablePictureInPicture;
 };
 
 partial interface Document {
   readonly attribute boolean pictureInPictureEnabled;
 
-  Promise<void> exitPictureInPicture();
+  [NewObject] Promise<void> exitPictureInPicture();
 };
 
 partial interface DocumentOrShadowRoot {
diff --git a/testing/web-platform/tests/picture-in-picture/idlharness.window.js b/testing/web-platform/tests/picture-in-picture/idlharness.window.js
index d86c676c9d98..e10bc0598b71 100644
--- a/testing/web-platform/tests/picture-in-picture/idlharness.window.js
+++ b/testing/web-platform/tests/picture-in-picture/idlharness.window.js
@@ -1,22 +1,31 @@
 // META: script=/resources/WebIDLParser.js
 // META: script=/resources/idlharness.js
+// META: script=resources/picture-in-picture-helpers.js
 
 'use strict';
 
 // https://wicg.github.io/picture-in-picture/
 
 promise_test(async () => {
-  const srcs = ['html', 'dom', 'picture-in-picture'];
-  const [html, dom, pip] = await Promise.all(
-      srcs.map(i => fetch(`/interfaces/${i}.idl`).then(r => r.text())));
+  try {
+    const video = await loadVideo();
+    document.body.appendChild(video);
+    self.video = video;
+    self.pipw = await video.requestPictureInPicture();
+  } catch (e) {
+    // Will be surfaced when video/pipw are undefined below.
+  }
 
-  const idl_array = new IdlArray();
-  idl_array.add_idls(pip);
-  idl_array.add_dependency_idls(dom);
-  idl_array.add_dependency_idls(html);
-
-  idl_array.add_objects({
-    Document: ['document'],
-  });
-  idl_array.test();
-}, 'picture-in-picture interfaces.');
+  idl_test(
+    ['picture-in-picture'],
+    ['html', 'dom'],
+    idl_array => {
+      idl_array.add_objects({
+        Document: ['document'],
+        DocumentOrShadowRoot: ['document'],
+        HTMLVideoElement: ['video'],
+        PictureInPictureWindow: ['pipw'],
+      });
+    },
+    'picture-in-picture interfaces.');
+})