diff --git a/testing/web-platform/meta/html/cross-origin-opener/new_window_same_site.html.ini b/testing/web-platform/meta/html/cross-origin-opener/new_window_same_site.html.ini
new file mode 100644
index 000000000000..610c71830b67
--- /dev/null
+++ b/testing/web-platform/meta/html/cross-origin-opener/new_window_same_site.html.ini
@@ -0,0 +1,2 @@
+[new_window_same_site.html]
+  prefs: [browser.tabs.remote.useCrossOriginOpenerPolicy:true]
diff --git a/testing/web-platform/tests/html/cross-origin-opener/new_window_same_site.html b/testing/web-platform/tests/html/cross-origin-opener/new_window_same_site.html
new file mode 100644
index 000000000000..b75f7ff7a646
--- /dev/null
+++ b/testing/web-platform/tests/html/cross-origin-opener/new_window_same_site.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<meta charset=utf-8>
+<script src=/resources/testharness.js></script>
+<script src=/resources/testharnessreport.js></script>
+<script src="/common/get-host-info.sub.js"></script>
+
+<script>
+
+const CHANNEL_NAME = "new_window_same_site";
+
+async_test(t => {
+  let w = window.open(`${get_host_info().HTTP_REMOTE_ORIGIN}/html/cross-origin-opener/resources/window.sub.html?channel=${CHANNEL_NAME}`, "window_name", "height=200,width=250");
+
+  // w will be closed by its postback iframe. When out of process,
+  // window.close() does not work.
+  t.add_cleanup(() => w.close());
+
+  let bc = new BroadcastChannel(CHANNEL_NAME);
+  bc.onmessage = t.step_func_done((event) => {
+    let payload = event.data;
+    assert_equals(payload.name, "window_name");
+    assert_equals(payload.opener, true);
+  });
+}, "same-site policy works");
+
+</script>
diff --git a/testing/web-platform/tests/html/cross-origin-opener/new_window_same_site.html.headers b/testing/web-platform/tests/html/cross-origin-opener/new_window_same_site.html.headers
new file mode 100644
index 000000000000..34bd099a302f
--- /dev/null
+++ b/testing/web-platform/tests/html/cross-origin-opener/new_window_same_site.html.headers
@@ -0,0 +1 @@
+Cross-Origin-Opener-Policy: same-site
diff --git a/testing/web-platform/tests/html/cross-origin-opener/resources/postback.sub.html b/testing/web-platform/tests/html/cross-origin-opener/resources/postback.sub.html
new file mode 100644
index 000000000000..ee08bab4d55e
--- /dev/null
+++ b/testing/web-platform/tests/html/cross-origin-opener/resources/postback.sub.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<meta charset=utf-8>
+
+<script>
+
+let channelName = new URL(location).searchParams.get("channel");
+let bc = new BroadcastChannel(channelName);
+window.addEventListener("message", (event) => {
+  bc.postMessage(event.data);
+  window.parent.close();
+}, false);
+
+</script>
diff --git a/testing/web-platform/tests/html/cross-origin-opener/resources/window.sub.html b/testing/web-platform/tests/html/cross-origin-opener/resources/window.sub.html
new file mode 100644
index 000000000000..7c72f87c3ddd
--- /dev/null
+++ b/testing/web-platform/tests/html/cross-origin-opener/resources/window.sub.html
@@ -0,0 +1,18 @@
+<!doctype html>
+<meta charset=utf-8>
+
+<script src="/common/get-host-info.sub.js"></script>
+<div id="status"> </div>
+
+<script type="text/javascript">
+
+  let iframe = document.createElement("iframe");
+  iframe.onload = () => {
+    let payload = { name: self.name, opener: !!self.opener };
+    iframe.contentWindow.postMessage(payload, "*");
+  };
+  let channelName = new URL(location).searchParams.get("channel");
+  iframe.src = `${get_host_info().HTTP_ORIGIN}/html/cross-origin-opener/resources/postback.sub.html?channel=${channelName}`;
+  document.body.appendChild(iframe);
+
+</script>
diff --git a/testing/web-platform/tests/html/cross-origin-opener/resources/window.sub.html.headers b/testing/web-platform/tests/html/cross-origin-opener/resources/window.sub.html.headers
new file mode 100644
index 000000000000..34bd099a302f
--- /dev/null
+++ b/testing/web-platform/tests/html/cross-origin-opener/resources/window.sub.html.headers
@@ -0,0 +1 @@
+Cross-Origin-Opener-Policy: same-site
