diff --git a/test/fixtures/wpt/README.md b/test/fixtures/wpt/README.md
index 6a3c5a845ec32d..09b1e2f3e45827 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/f8821adb28/dom/events
-- encoding: https://github.com/web-platform-tests/wpt/tree/c1b24fce6e/encoding
+- encoding: https://github.com/web-platform-tests/wpt/tree/779d175c40/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/unsupported-labels.window.js b/test/fixtures/wpt/encoding/unsupported-labels.window.js
new file mode 100644
index 00000000000000..1668a36f234094
--- /dev/null
+++ b/test/fixtures/wpt/encoding/unsupported-labels.window.js
@@ -0,0 +1,178 @@
+// This list was inspired by these sources:
+// - https://annevankesteren.nl/2010/8-bit-labels
+// - http://l0.cm/encodings/table/
+
+[
+  "437",
+  "adobe-standard-encoding",
+  "armscii-8",
+  "bocu-1",
+  "cesu-8",
+  "cp1025",
+  "cp437",
+  "cp737",
+  "cp851",
+  "cp858",
+  "cp862",
+  "cp864",
+  "cp869",
+  "cp875",
+  "cp950",
+  "csiso103t618bit",
+  "csiso111ecmacyrillic",
+  "cspc8codepage437",
+  "csviscii",
+  "dos-720",
+  "dos-862",
+  "ecma-cyrillic",
+  "euc-tw",
+  "german",
+  "geostd8",
+  "hp-roman8",
+  "ibm-thai",
+  "ibm00858",
+  "ibm00924",
+  "ibm01047",
+  "ibm01140",
+  "ibm01141",
+  "ibm01142",
+  "ibm01143",
+  "ibm01144",
+  "ibm01145",
+  "ibm01146",
+  "ibm01147",
+  "ibm01148",
+  "ibm01149",
+  "ibm037",
+  "ibm1026",
+  "ibm1047",
+  "ibm273",
+  "ibm277",
+  "ibm278",
+  "ibm280",
+  "ibm284",
+  "ibm285",
+  "ibm290",
+  "ibm297",
+  "ibm367",
+  "ibm420",
+  "ibm423",
+  "ibm424",
+  "ibm437",
+  "ibm500",
+  "ibm737",
+  "ibm775",
+  "ibm850",
+  "ibm852",
+  "ibm855",
+  "ibm857",
+  "ibm860",
+  "ibm861",
+  "ibm862",
+  "ibm863",
+  "ibm864",
+  "ibm864i",
+  "ibm865",
+  "ibm868",
+  "ibm869",
+  "ibm870",
+  "ibm871",
+  "ibm880",
+  "ibm905",
+  "ibm918",
+  "iso-2022-jp-1",
+  "iso-2022-jp-2",
+  "iso-2022-jp-3",
+  "iso-8859-8 visual",
+  "jis_c6226-1978",
+  "jis_x0208-1983",
+  "jis_x0208-1990",
+  "jis_x0212-1990",
+  "johab",
+  "latin9",
+  "norwegian",
+  "sami-ws2",
+  "scsu",
+  "shift_jis_x0213-2000",
+  "swedish",
+  "tcvn",
+  "tis-620-2533",
+  "utf-7",
+  "utf-32",
+  "viscii",
+  "windows-936-2000",
+  "windows-sami-2",
+  "ws2",
+  "x-chinese-cns",
+  "x-chinese-eten",
+  "x-cp20001",
+  "x-cp20003",
+  "x-cp20004",
+  "x-cp20005",
+  "x-cp20261",
+  "x-cp20269",
+  "x-cp20936",
+  "x-cp20949",
+  "x-cp21027",
+  "x-cp50227",
+  "x-cp50229",
+  "x-ebcdic-koreanextended",
+  "x-europa",
+  "x-ia5",
+  "x-ia5-german",
+  "x-ia5-norwegian",
+  "x-ia5-swedish",
+  "x-iscii-as",
+  "x-iscii-be",
+  "x-iscii-de",
+  "x-iscii-gu",
+  "x-iscii-ka",
+  "x-iscii-ma",
+  "x-iscii-or",
+  "x-iscii-pa",
+  "x-iscii-t",
+  "x-iscii-ta",
+  "x-iscii-te",
+  "x-mac-arabic",
+  "x-mac-ce",
+  "x-mac-centraleurroman",
+  "x-mac-chinesesimp",
+  "x-mac-chinesetrad",
+  "x-mac-croatian",
+  "x-mac-devanagari",
+  "x-mac-dingbats",
+  "x-mac-farsi",
+  "x-mac-greek",
+  "x-mac-gujarati",
+  "x-mac-gurmukhi",
+  "x-mac-hebrew",
+  "x-mac-icelandic",
+  "x-mac-japanese",
+  "x-mac-korean",
+  "x-mac-roman-latin1",
+  "x-mac-romanian",
+  "x-mac-symbol",
+  "x-mac-thai",
+  "x-mac-tibetan",
+  "x-mac-turkish",
+  "x-mac-vt100",
+  "x-nextstep",
+  "x-vps",
+  "_autodetect",
+  "_autodetect_all",
+  "_autodetect_kr"
+].forEach(label => {
+  async_test(t => {
+    const frame = document.createElement("iframe");
+    t.add_cleanup(() => {
+      frame.remove();
+    });
+    frame.src = "resources/text-plain-charset.py?label=" + label;
+    frame.onload = t.step_func_done(() => {
+      // If we ever change this default this needs adjusting accordingly.
+      assert_equals(frame.contentDocument.characterSet, "windows-1252");
+      assert_equals(frame.contentDocument.inputEncoding, "windows-1252");
+    });
+    document.body.append(frame);
+  }, `${label} is not supported by the Encoding Standard`);
+});
diff --git a/test/fixtures/wpt/versions.json b/test/fixtures/wpt/versions.json
index cdbaee5e4aadae..988b6f925ad668 100644
--- a/test/fixtures/wpt/versions.json
+++ b/test/fixtures/wpt/versions.json
@@ -16,7 +16,7 @@
     "path": "dom/events"
   },
   "encoding": {
-    "commit": "c1b24fce6e625c1b79124a58f27bf9adce02d5d7",
+    "commit": "779d175c40efcb8f2c9512bebe25ffbeda485708",
     "path": "encoding"
   },
   "fetch/data-urls/resources": {
diff --git a/test/wpt/status/encoding.json b/test/wpt/status/encoding.json
index ed98d966297ce2..411bc3401b04c1 100644
--- a/test/wpt/status/encoding.json
+++ b/test/wpt/status/encoding.json
@@ -95,5 +95,8 @@
   },
   "textdecoder-eof.any.js": {
     "requires": ["small-icu"]
+  },
+  "unsupported-labels.window.js": {
+    "skip": "document is not defined"
   }
 }