diff --git a/test/fixtures/wpt/README.md b/test/fixtures/wpt/README.md
index 958f67474d931e..60051695f94957 100644
--- a/test/fixtures/wpt/README.md
+++ b/test/fixtures/wpt/README.md
@@ -14,7 +14,7 @@ Last update:
 - console: https://github.com/web-platform-tests/wpt/tree/767ae35464/console
 - dom/abort: https://github.com/web-platform-tests/wpt/tree/8fadb38120/dom/abort
 - dom/events: https://github.com/web-platform-tests/wpt/tree/ab8999891c/dom/events
-- encoding: https://github.com/web-platform-tests/wpt/tree/779d175c40/encoding
+- encoding: https://github.com/web-platform-tests/wpt/tree/0c1b9d1622/encoding
 - fetch/data-urls/resources: https://github.com/web-platform-tests/wpt/tree/7c79d998ff/fetch/data-urls/resources
 - FileAPI: https://github.com/web-platform-tests/wpt/tree/3b279420d4/FileAPI
 - FileAPI/file: https://github.com/web-platform-tests/wpt/tree/c01f637cca/FileAPI/file
diff --git a/test/fixtures/wpt/encoding/streams/invalid-realm.window.js b/test/fixtures/wpt/encoding/streams/invalid-realm.window.js
new file mode 100644
index 00000000000000..beaec42641fe8d
--- /dev/null
+++ b/test/fixtures/wpt/encoding/streams/invalid-realm.window.js
@@ -0,0 +1,37 @@
+// Text*Stream should still work even if the realm is detached.
+
+// Adds an iframe to the document and returns it.
+function addIframe() {
+  const iframe = document.createElement('iframe');
+  document.body.appendChild(iframe);
+  return iframe;
+}
+
+promise_test(async t => {
+  const iframe = addIframe();
+  const stream = new iframe.contentWindow.TextDecoderStream();
+  const readPromise = stream.readable.getReader().read();
+  const writer = stream.writable.getWriter();
+  await writer.ready;
+  iframe.remove();
+  return Promise.all([writer.write(new Uint8Array([65])),readPromise]);
+}, 'TextDecoderStream: write in detached realm should succeed');
+
+promise_test(async t => {
+  const iframe = addIframe();
+  const stream = new iframe.contentWindow.TextEncoderStream();
+  const readPromise = stream.readable.getReader().read();
+  const writer = stream.writable.getWriter();
+  await writer.ready;
+  iframe.remove();
+  return Promise.all([writer.write('A'), readPromise]);
+}, 'TextEncoderStream: write in detached realm should succeed');
+
+for (const type of ['TextEncoderStream', 'TextDecoderStream']) {
+  promise_test(async t => {
+    const iframe = addIframe();
+    const stream = new iframe.contentWindow[type]();
+    iframe.remove();
+    return stream.writable.close();
+  }, `${type}: close in detached realm should succeed`);
+}
diff --git a/test/fixtures/wpt/versions.json b/test/fixtures/wpt/versions.json
index 768418a65aeab3..b118fe273558c1 100644
--- a/test/fixtures/wpt/versions.json
+++ b/test/fixtures/wpt/versions.json
@@ -16,7 +16,7 @@
     "path": "dom/events"
   },
   "encoding": {
-    "commit": "779d175c40efcb8f2c9512bebe25ffbeda485708",
+    "commit": "0c1b9d1622ae0f27f82d7f7d7a1e9e69d410a3ca",
     "path": "encoding"
   },
   "fetch/data-urls/resources": {
diff --git a/test/wpt/status/encoding.json b/test/wpt/status/encoding.json
index f39fc321f2a210..0cc551e24a25d9 100644
--- a/test/wpt/status/encoding.json
+++ b/test/wpt/status/encoding.json
@@ -48,6 +48,9 @@
   "streams/decode-ignore-bom.any.js": {
     "requires": ["small-icu"]
   },
+  "streams/invalid-realm.window.js": {
+    "skip": "document is not defined"
+  },
   "streams/realms.window.js": {
     "skip": "window is not defined"
   },