diff --git a/beacon/beacon-readablestream.window.js b/beacon/beacon-readablestream.window.js
new file mode 100644
index 00000000000000..fc7f81f884bdf4
--- /dev/null
+++ b/beacon/beacon-readablestream.window.js
@@ -0,0 +1,3 @@
+test(() => {
+  assert_throws(new TypeError(), () => navigator.sendBeacon("...", new ReadableStream()));
+}, "sendBeacon() with a stream does not work due to the keepalive flag being set");
diff --git a/fetch/api/request/request-init-stream.any.js b/fetch/api/request/request-init-stream.any.js
new file mode 100644
index 00000000000000..22e3f41bc2d8a3
--- /dev/null
+++ b/fetch/api/request/request-init-stream.any.js
@@ -0,0 +1,51 @@
+// META: global=window,worker
+
+"use strict";
+
+async function assert_request(input, init) {
+  assert_throws(new TypeError(), () => new Request(input, init), "new Request()");
+  assert_throws(new TypeError(), async () => await fetch(input, init), "fetch()");
+}
+
+promise_test(async () => {
+  const stream = new ReadableStream();
+  stream.getReader();
+  await assert_request("...", { method:"POST", body: stream });
+}, "Constructing a Request with a stream on which getReader() is called");
+
+promise_test(async () => {
+  const stream = new ReadableStream();
+  stream.getReader().read();
+  await assert_request("...", { method:"POST", body: stream });
+}, "Constructing a Request with a stream on which read() is called");
+
+promise_test(async () => {
+  const stream = new ReadableStream({ pull: c => c.enqueue(new Uint8Array()) }),
+        reader = stream.getReader();
+  await reader.read();
+  reader.releaseLock();
+  await assert_request("...", { method:"POST", body: stream });
+}, "Constructing a Request with a stream on which read() and releaseLock() are called");
+
+promise_test(async () => {
+  const request = new Request("...", { method: "POST", body: "..." });
+  request.body.getReader();
+  await assert_request(request);
+  assert_class_string(new Request(request, { body: "..." }), "Request");
+}, "Constructing a Request with a Request on which body.getReader() is called");
+
+promise_test(async () => {
+  const request = new Request("...", { method: "POST", body: "..." });
+  request.body.getReader().read();
+  await assert_request(request);
+  assert_class_string(new Request(request, { body: "..." }), "Request");
+}, "Constructing a Request with a Request on which body.getReader().read() is called");
+
+promise_test(async () => {
+  const request = new Request("...", { method: "POST", body: "..." }),
+        reader = request.body.getReader();
+  await reader.read();
+  reader.releaseLock();
+  await assert_request(request);
+  assert_class_string(new Request(request, { body: "..." }), "Request");
+}, "Constructing a Request with a Request on which read() and releaseLock() are called");
diff --git a/fetch/api/response/response-from-stream.any.js b/fetch/api/response/response-from-stream.any.js
new file mode 100644
index 00000000000000..93b29b42867f47
--- /dev/null
+++ b/fetch/api/response/response-from-stream.any.js
@@ -0,0 +1,23 @@
+// META: global=window,worker
+
+"use strict";
+
+test(() => {
+  const stream = new ReadableStream();
+  stream.getReader();
+  assert_throws(new TypeError(), () => new Response(stream));
+}, "Constructing a Response with a stream on which getReader() is called");
+
+test(() => {
+  const stream = new ReadableStream();
+  stream.getReader().read();
+  assert_throws(new TypeError(), () => new Response(stream));
+}, "Constructing a Response with a stream on which read() is called");
+
+promise_test(async () => {
+  const stream = new ReadableStream({ pull: c => c.enqueue(new Uint8Array()) }),
+        reader = stream.getReader();
+  await reader.read();
+  reader.releaseLock();
+  assert_throws(new TypeError(), () => new Response(stream));
+}, "Constructing a Response with a stream on which read() and releaseLock() are called");
diff --git a/xhr/send-data-readablestream.any.js b/xhr/send-data-readablestream.any.js
new file mode 100644
index 00000000000000..cca6e76a042cc8
--- /dev/null
+++ b/xhr/send-data-readablestream.any.js
@@ -0,0 +1,27 @@
+// META: global=window,dedicatedworker,sharedworker
+
+function assert_xhr(stream) {
+  const client = new XMLHttpRequest();
+  client.open("POST", "...");
+  assert_throws(new TypeError(), () => client.send(stream));
+}
+
+test(() => {
+  const stream = new ReadableStream();
+  stream.getReader();
+  assert_xhr(stream);
+}, "XMLHttpRequest: send() with a stream on which getReader() is called");
+
+test(() => {
+  const stream = new ReadableStream();
+  stream.getReader().read();
+  assert_xhr(stream);
+}, "XMLHttpRequest: send() with a stream on which read() is called");
+
+promise_test(async () => {
+  const stream = new ReadableStream({ pull: c => c.enqueue(new Uint8Array()) }),
+        reader = stream.getReader();
+  await reader.read();
+  reader.releaseLock();
+  assert_xhr(stream);
+}, "XMLHttpRequest: send() with a stream on which read() and releaseLock() are called");