diff --git a/packages/bun-types/bun.d.ts b/packages/bun-types/bun.d.ts
index d8c9402e2871..44ca4f6af31f 100644
--- a/packages/bun-types/bun.d.ts
+++ b/packages/bun-types/bun.d.ts
@@ -28,7 +28,277 @@ declare module "bun" {
   type ReadableStreamReader<T> = ReadableStreamDefaultReader<T>;
   type Transferable = ArrayBuffer | MessagePort;
   type MessageEventSource = Bun.__internal.UseLibDomIfAvailable<"MessageEventSource", undefined>;
-  type Encoding = "utf-8" | "windows-1252" | "utf-16";
+  /**
+   * An encoding label from the WHATWG Encoding Standard, as accepted by the
+   * `TextDecoder` constructor.
+   *
+   * The labels of the `replacement` encoding are excluded: the `TextDecoder`
+   * constructor rejects them with a `RangeError`.
+   *
+   * @see https://encoding.spec.whatwg.org/#names-and-labels
+   */
+  type Encoding =
+    // utf-8
+    | "unicode-1-1-utf-8"
+    | "unicode11utf8"
+    | "unicode20utf8"
+    | "utf-8"
+    | "utf8"
+    | "x-unicode20utf8"
+    // ibm866
+    | "866"
+    | "cp866"
+    | "csibm866"
+    | "ibm866"
+    // iso-8859-2
+    | "csisolatin2"
+    | "iso-8859-2"
+    | "iso-ir-101"
+    | "iso8859-2"
+    | "iso88592"
+    | "iso_8859-2"
+    | "iso_8859-2:1987"
+    | "l2"
+    | "latin2"
+    // iso-8859-3
+    | "csisolatin3"
+    | "iso-8859-3"
+    | "iso-ir-109"
+    | "iso8859-3"
+    | "iso88593"
+    | "iso_8859-3"
+    | "iso_8859-3:1988"
+    | "l3"
+    | "latin3"
+    // iso-8859-4
+    | "csisolatin4"
+    | "iso-8859-4"
+    | "iso-ir-110"
+    | "iso8859-4"
+    | "iso88594"
+    | "iso_8859-4"
+    | "iso_8859-4:1988"
+    | "l4"
+    | "latin4"
+    // iso-8859-5
+    | "csisolatincyrillic"
+    | "cyrillic"
+    | "iso-8859-5"
+    | "iso-ir-144"
+    | "iso8859-5"
+    | "iso88595"
+    | "iso_8859-5"
+    | "iso_8859-5:1988"
+    // iso-8859-6
+    | "arabic"
+    | "asmo-708"
+    | "csiso88596e"
+    | "csiso88596i"
+    | "csisolatinarabic"
+    | "ecma-114"
+    | "iso-8859-6"
+    | "iso-8859-6-e"
+    | "iso-8859-6-i"
+    | "iso-ir-127"
+    | "iso8859-6"
+    | "iso88596"
+    | "iso_8859-6"
+    | "iso_8859-6:1987"
+    // iso-8859-7
+    | "csisolatingreek"
+    | "ecma-118"
+    | "elot_928"
+    | "greek"
+    | "greek8"
+    | "iso-8859-7"
+    | "iso-ir-126"
+    | "iso8859-7"
+    | "iso88597"
+    | "iso_8859-7"
+    | "iso_8859-7:1987"
+    | "sun_eu_greek"
+    // iso-8859-8
+    | "csiso88598e"
+    | "csisolatinhebrew"
+    | "hebrew"
+    | "iso-8859-8"
+    | "iso-8859-8-e"
+    | "iso-ir-138"
+    | "iso8859-8"
+    | "iso88598"
+    | "iso_8859-8"
+    | "iso_8859-8:1988"
+    | "visual"
+    // iso-8859-8-i
+    | "csiso88598i"
+    | "iso-8859-8-i"
+    | "logical"
+    // iso-8859-10
+    | "csisolatin6"
+    | "iso-8859-10"
+    | "iso-ir-157"
+    | "iso8859-10"
+    | "iso885910"
+    | "l6"
+    | "latin6"
+    // iso-8859-13
+    | "iso-8859-13"
+    | "iso8859-13"
+    | "iso885913"
+    // iso-8859-14
+    | "iso-8859-14"
+    | "iso8859-14"
+    | "iso885914"
+    // iso-8859-15
+    | "csisolatin9"
+    | "iso-8859-15"
+    | "iso8859-15"
+    | "iso885915"
+    | "iso_8859-15"
+    | "l9"
+    // iso-8859-16
+    | "iso-8859-16"
+    // koi8-r
+    | "cskoi8r"
+    | "koi"
+    | "koi8"
+    | "koi8-r"
+    | "koi8_r"
+    // koi8-u
+    | "koi8-ru"
+    | "koi8-u"
+    // macintosh
+    | "csmacintosh"
+    | "mac"
+    | "macintosh"
+    | "x-mac-roman"
+    // windows-874
+    | "dos-874"
+    | "iso-8859-11"
+    | "iso8859-11"
+    | "iso885911"
+    | "tis-620"
+    | "windows-874"
+    // windows-1250
+    | "cp1250"
+    | "windows-1250"
+    | "x-cp1250"
+    // windows-1251
+    | "cp1251"
+    | "windows-1251"
+    | "x-cp1251"
+    // windows-1252
+    | "ansi_x3.4-1968"
+    | "ascii"
+    | "cp1252"
+    | "cp819"
+    | "csisolatin1"
+    | "ibm819"
+    | "iso-8859-1"
+    | "iso-ir-100"
+    | "iso8859-1"
+    | "iso88591"
+    | "iso_8859-1"
+    | "iso_8859-1:1987"
+    | "l1"
+    | "latin1"
+    | "us-ascii"
+    | "windows-1252"
+    | "x-cp1252"
+    // windows-1253
+    | "cp1253"
+    | "windows-1253"
+    | "x-cp1253"
+    // windows-1254
+    | "cp1254"
+    | "csisolatin5"
+    | "iso-8859-9"
+    | "iso-ir-148"
+    | "iso8859-9"
+    | "iso88599"
+    | "iso_8859-9"
+    | "iso_8859-9:1989"
+    | "l5"
+    | "latin5"
+    | "windows-1254"
+    | "x-cp1254"
+    // windows-1255
+    | "cp1255"
+    | "windows-1255"
+    | "x-cp1255"
+    // windows-1256
+    | "cp1256"
+    | "windows-1256"
+    | "x-cp1256"
+    // windows-1257
+    | "cp1257"
+    | "windows-1257"
+    | "x-cp1257"
+    // windows-1258
+    | "cp1258"
+    | "windows-1258"
+    | "x-cp1258"
+    // x-mac-cyrillic
+    | "x-mac-cyrillic"
+    | "x-mac-ukrainian"
+    // gbk
+    | "chinese"
+    | "csgb2312"
+    | "csiso58gb231280"
+    | "gb2312"
+    | "gb_2312"
+    | "gb_2312-80"
+    | "gbk"
+    | "iso-ir-58"
+    | "x-gbk"
+    // gb18030
+    | "gb18030"
+    // big5
+    | "big5"
+    | "big5-hkscs"
+    | "cn-big5"
+    | "csbig5"
+    | "x-x-big5"
+    // euc-jp
+    | "cseucpkdfmtjapanese"
+    | "euc-jp"
+    | "x-euc-jp"
+    // iso-2022-jp
+    | "csiso2022jp"
+    | "iso-2022-jp"
+    // shift_jis
+    | "csshiftjis"
+    | "ms932"
+    | "ms_kanji"
+    | "shift-jis"
+    | "shift_jis"
+    | "sjis"
+    | "windows-31j"
+    | "x-sjis"
+    // euc-kr
+    | "cseuckr"
+    | "csksc56011987"
+    | "euc-kr"
+    | "iso-ir-149"
+    | "korean"
+    | "ks_c_5601-1987"
+    | "ks_c_5601-1989"
+    | "ksc5601"
+    | "ksc_5601"
+    | "windows-949"
+    // utf-16be
+    | "unicodefffe"
+    | "utf-16be"
+    // utf-16le
+    | "csunicode"
+    | "iso-10646-ucs-2"
+    | "ucs-2"
+    | "unicode"
+    | "unicodefeff"
+    | "utf-16"
+    | "utf-16le"
+    // x-user-defined
+    | "x-user-defined";
   type UncaughtExceptionOrigin = "uncaughtException" | "unhandledRejection";
   type MultipleResolveType = "resolve" | "reject";
   type BeforeExitListener = (code: number) => void;
diff --git a/packages/bun-types/globals.d.ts b/packages/bun-types/globals.d.ts
index 939c7c2a2825..51ee5a7adf20 100644
--- a/packages/bun-types/globals.d.ts
+++ b/packages/bun-types/globals.d.ts
@@ -252,8 +252,9 @@ declare var TextEncoder: Bun.__internal.UseLibDomIfAvailable<
 >;
 
 /**
- * An implementation of the [WHATWG Encoding Standard](https://encoding.spec.whatwg.org/) `TextDecoder` API. All
- * instances of `TextDecoder` only support UTF-8 decoding.
+ * An implementation of the [WHATWG Encoding Standard](https://encoding.spec.whatwg.org/) `TextDecoder` API.
+ * Supports every encoding label the standard defines, except the labels of the
+ * `replacement` encoding.
  *
  * ```js
  * const decoder = new TextDecoder();
diff --git a/test/integration/bun-types/bun-types.test.ts b/test/integration/bun-types/bun-types.test.ts
index 05fa801f45e5..2f77af470c4f 100644
--- a/test/integration/bun-types/bun-types.test.ts
+++ b/test/integration/bun-types/bun-types.test.ts
@@ -400,6 +400,80 @@ describe("@types/bun integration test", () => {
     });
   });
 
+  // Runs on debug builds too, same as the Bun.mmap block above.
+  describe("TextDecoder", () => {
+    test("accepts the encoding labels the runtime supports", async () => {
+      const checkDir = join(TEMP_DIR, "text-decoder-encoding-check");
+      const tsconfig = structuredClone(sourceTsconfig);
+      tsconfig.include = ["text-decoder-encodings.ts"];
+      tsconfig.compilerOptions.typeRoots = [join(BASE_FIXTURE_DIR, "node_modules", "@types")];
+      await mkdir(checkDir, { recursive: true });
+      await makeTree(checkDir, {
+        "tsconfig.json": JSON.stringify(tsconfig, null, 2),
+        "text-decoder-encodings.ts": `new TextDecoder("windows-1251");
+           new TextDecoder("shift_jis");
+           new TextDecoder("utf8");
+           new TextDecoder("latin1");
+           new TextDecoder("gb18030", { fatal: true, ignoreBOM: true });
+           // @ts-expect-error - the TextDecoder constructor rejects the replacement encoding
+           "hz-gb-2312" satisfies Bun.Encoding;
+           // @ts-expect-error - not a label the Encoding Standard defines
+           "utf-99" satisfies Bun.Encoding;`,
+      });
+
+      await using proc = Bun.spawn({
+        cmd: [bunExe(), join(BASE_FIXTURE_DIR, "node_modules", "typescript", "bin", "tsc"), "-p", "."],
+        env: bunEnv,
+        cwd: checkDir,
+        stdout: "pipe",
+        stderr: "pipe",
+      });
+
+      const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+
+      expect(stderr.trim()).toBe("");
+      expect(stdout.trim()).toBe("");
+      expect(exitCode).toBe(0);
+    });
+
+    // tsc cannot read the runtime's label table in
+    // src/runtime/webcore/EncodingLabel.rs, so the fixture carries a literal
+    // copy. This check ties that copy to the running binary: every fixture
+    // label must construct, and the replacement labels must throw.
+    test("the fixture label table matches the runtime", () => {
+      const fixture = readFileSync(join(FIXTURE_SOURCE_DIR, "text-encode-decoder.ts"), "utf8");
+      const arrayStart = fixture.indexOf("const labels = [");
+      const arrayEnd = fixture.indexOf("] as const;", arrayStart);
+      expect(arrayStart).toBeGreaterThan(-1);
+      expect(arrayEnd).toBeGreaterThan(arrayStart);
+
+      const labels = [...fixture.slice(arrayStart, arrayEnd).matchAll(/"([^"]+)"/g)].map(m => m[1]);
+      expect(labels).toHaveLength(222);
+      expect(new Set(labels).size).toBe(labels.length);
+
+      const rejected = labels.filter(label => {
+        try {
+          new TextDecoder(label as Bun.Encoding);
+          return false;
+        } catch {
+          return true;
+        }
+      });
+      expect(rejected).toEqual([]);
+
+      for (const label of [
+        "csiso2022kr",
+        "hz-gb-2312",
+        "iso-2022-cn",
+        "iso-2022-cn-ext",
+        "iso-2022-kr",
+        "replacement",
+      ]) {
+        expect(() => new TextDecoder(label as Bun.Encoding)).toThrow(RangeError);
+      }
+    });
+  });
+
   describe("Test Globals", () => {
     const code = `
       const test_shouldBeAFunction: Function = test;
diff --git a/test/integration/bun-types/fixture/text-encode-decoder.ts b/test/integration/bun-types/fixture/text-encode-decoder.ts
index f2eff6760e20..47c42049d901 100644
--- a/test/integration/bun-types/fixture/text-encode-decoder.ts
+++ b/test/integration/bun-types/fixture/text-encode-decoder.ts
@@ -1,220 +1,295 @@
-// This test is currently failing, but it's not so important that it blocks a release
+// The label table from https://encoding.spec.whatwg.org/#names-and-labels,
+// minus the replacement encoding's labels (the TextDecoder constructor
+// rejects those with a RangeError). Keep in sync with Bun.Encoding in
+// packages/bun-types/bun.d.ts and src/runtime/webcore/EncodingLabel.rs.
+const labels = [
+  // utf-8
+  "unicode-1-1-utf-8",
+  "unicode11utf8",
+  "unicode20utf8",
+  "utf-8",
+  "utf8",
+  "x-unicode20utf8",
+  // ibm866
+  "866",
+  "cp866",
+  "csibm866",
+  "ibm866",
+  // iso-8859-2
+  "csisolatin2",
+  "iso-8859-2",
+  "iso-ir-101",
+  "iso8859-2",
+  "iso88592",
+  "iso_8859-2",
+  "iso_8859-2:1987",
+  "l2",
+  "latin2",
+  // iso-8859-3
+  "csisolatin3",
+  "iso-8859-3",
+  "iso-ir-109",
+  "iso8859-3",
+  "iso88593",
+  "iso_8859-3",
+  "iso_8859-3:1988",
+  "l3",
+  "latin3",
+  // iso-8859-4
+  "csisolatin4",
+  "iso-8859-4",
+  "iso-ir-110",
+  "iso8859-4",
+  "iso88594",
+  "iso_8859-4",
+  "iso_8859-4:1988",
+  "l4",
+  "latin4",
+  // iso-8859-5
+  "csisolatincyrillic",
+  "cyrillic",
+  "iso-8859-5",
+  "iso-ir-144",
+  "iso8859-5",
+  "iso88595",
+  "iso_8859-5",
+  "iso_8859-5:1988",
+  // iso-8859-6
+  "arabic",
+  "asmo-708",
+  "csiso88596e",
+  "csiso88596i",
+  "csisolatinarabic",
+  "ecma-114",
+  "iso-8859-6",
+  "iso-8859-6-e",
+  "iso-8859-6-i",
+  "iso-ir-127",
+  "iso8859-6",
+  "iso88596",
+  "iso_8859-6",
+  "iso_8859-6:1987",
+  // iso-8859-7
+  "csisolatingreek",
+  "ecma-118",
+  "elot_928",
+  "greek",
+  "greek8",
+  "iso-8859-7",
+  "iso-ir-126",
+  "iso8859-7",
+  "iso88597",
+  "iso_8859-7",
+  "iso_8859-7:1987",
+  "sun_eu_greek",
+  // iso-8859-8
+  "csiso88598e",
+  "csisolatinhebrew",
+  "hebrew",
+  "iso-8859-8",
+  "iso-8859-8-e",
+  "iso-ir-138",
+  "iso8859-8",
+  "iso88598",
+  "iso_8859-8",
+  "iso_8859-8:1988",
+  "visual",
+  // iso-8859-8-i
+  "csiso88598i",
+  "iso-8859-8-i",
+  "logical",
+  // iso-8859-10
+  "csisolatin6",
+  "iso-8859-10",
+  "iso-ir-157",
+  "iso8859-10",
+  "iso885910",
+  "l6",
+  "latin6",
+  // iso-8859-13
+  "iso-8859-13",
+  "iso8859-13",
+  "iso885913",
+  // iso-8859-14
+  "iso-8859-14",
+  "iso8859-14",
+  "iso885914",
+  // iso-8859-15
+  "csisolatin9",
+  "iso-8859-15",
+  "iso8859-15",
+  "iso885915",
+  "iso_8859-15",
+  "l9",
+  // iso-8859-16
+  "iso-8859-16",
+  // koi8-r
+  "cskoi8r",
+  "koi",
+  "koi8",
+  "koi8-r",
+  "koi8_r",
+  // koi8-u
+  "koi8-ru",
+  "koi8-u",
+  // macintosh
+  "csmacintosh",
+  "mac",
+  "macintosh",
+  "x-mac-roman",
+  // windows-874
+  "dos-874",
+  "iso-8859-11",
+  "iso8859-11",
+  "iso885911",
+  "tis-620",
+  "windows-874",
+  // windows-1250
+  "cp1250",
+  "windows-1250",
+  "x-cp1250",
+  // windows-1251
+  "cp1251",
+  "windows-1251",
+  "x-cp1251",
+  // windows-1252
+  "ansi_x3.4-1968",
+  "ascii",
+  "cp1252",
+  "cp819",
+  "csisolatin1",
+  "ibm819",
+  "iso-8859-1",
+  "iso-ir-100",
+  "iso8859-1",
+  "iso88591",
+  "iso_8859-1",
+  "iso_8859-1:1987",
+  "l1",
+  "latin1",
+  "us-ascii",
+  "windows-1252",
+  "x-cp1252",
+  // windows-1253
+  "cp1253",
+  "windows-1253",
+  "x-cp1253",
+  // windows-1254
+  "cp1254",
+  "csisolatin5",
+  "iso-8859-9",
+  "iso-ir-148",
+  "iso8859-9",
+  "iso88599",
+  "iso_8859-9",
+  "iso_8859-9:1989",
+  "l5",
+  "latin5",
+  "windows-1254",
+  "x-cp1254",
+  // windows-1255
+  "cp1255",
+  "windows-1255",
+  "x-cp1255",
+  // windows-1256
+  "cp1256",
+  "windows-1256",
+  "x-cp1256",
+  // windows-1257
+  "cp1257",
+  "windows-1257",
+  "x-cp1257",
+  // windows-1258
+  "cp1258",
+  "windows-1258",
+  "x-cp1258",
+  // x-mac-cyrillic
+  "x-mac-cyrillic",
+  "x-mac-ukrainian",
+  // gbk
+  "chinese",
+  "csgb2312",
+  "csiso58gb231280",
+  "gb2312",
+  "gb_2312",
+  "gb_2312-80",
+  "gbk",
+  "iso-ir-58",
+  "x-gbk",
+  // gb18030
+  "gb18030",
+  // big5
+  "big5",
+  "big5-hkscs",
+  "cn-big5",
+  "csbig5",
+  "x-x-big5",
+  // euc-jp
+  "cseucpkdfmtjapanese",
+  "euc-jp",
+  "x-euc-jp",
+  // iso-2022-jp
+  "csiso2022jp",
+  "iso-2022-jp",
+  // shift_jis
+  "csshiftjis",
+  "ms932",
+  "ms_kanji",
+  "shift-jis",
+  "shift_jis",
+  "sjis",
+  "windows-31j",
+  "x-sjis",
+  // euc-kr
+  "cseuckr",
+  "csksc56011987",
+  "euc-kr",
+  "iso-ir-149",
+  "korean",
+  "ks_c_5601-1987",
+  "ks_c_5601-1989",
+  "ksc5601",
+  "ksc_5601",
+  "windows-949",
+  // utf-16be
+  "unicodefffe",
+  "utf-16be",
+  // utf-16le
+  "csunicode",
+  "iso-10646-ucs-2",
+  "ucs-2",
+  "unicode",
+  "unicodefeff",
+  "utf-16",
+  "utf-16le",
+  // x-user-defined
+  "x-user-defined",
+] as const;
 
-// type utf_8 = "unicode-1-1-utf-8" | "utf-8" | "utf8";
-// type ibm866 = "866" | "cp866" | "csibm866" | "ibm866";
-// type iso_8859_2 =
-//   | "csisolatin2"
-//   | "iso-8859-2"
-//   | "iso-ir-101"
-//   | "iso8859-2"
-//   | "iso88592"
-//   | "iso_8859-2"
-//   | "iso_8859-2:1987"
-//   | "l2"
-//   | "latin2";
-// type iso_8859_3 =
-//   | "csisolatin3"
-//   | "iso-8859-3"
-//   | "iso-ir-109"
-//   | "iso8859-3"
-//   | "iso88593"
-//   | "iso_8859-3"
-//   | "iso_8859-3:1988"
-//   | "l3"
-//   | "latin3";
-// type iso_8859_4 =
-//   | "csisolatin4"
-//   | "iso-8859-4"
-//   | "iso-ir-110"
-//   | "iso8859-4"
-//   | "iso88594"
-//   | "iso_8859-4"
-//   | "iso_8859-4:1988"
-//   | "l4"
-//   | "latin4";
-// type iso_8859_5 =
-//   | "csisolatincyrillic"
-//   | "cyrillic"
-//   | "iso-8859-5"
-//   | "iso-ir-144"
-//   | "iso88595"
-//   | "iso_8859-5"
-//   | "iso_8859-5:1988";
-// type iso_8859_6 =
-//   | "arabic"
-//   | "asmo-708"
-//   | "csiso88596e"
-//   | "csiso88596i"
-//   | "csisolatinarabic"
-//   | "ecma-114"
-//   | "iso-8859-6"
-//   | "iso-8859-6-e"
-//   | "iso-8859-6-i"
-//   | "iso-ir-127"
-//   | "iso8859-6"
-//   | "iso88596"
-//   | "iso_8859-6"
-//   | "iso_8859-6:1987";
-// type iso_8859_7 =
-//   | "csisolatingreek"
-//   | "ecma-118"
-//   | "elot_928"
-//   | "greek"
-//   | "greek8"
-//   | "iso-8859-7"
-//   | "iso-ir-126"
-//   | "iso8859-7"
-//   | "iso88597"
-//   | "iso_8859-7"
-//   | "iso_8859-7:1987"
-//   | "sun_eu_greek";
-// type iso_8859_8 =
-//   | "csiso88598e"
-//   | "csisolatinhebrew"
-//   | "hebrew"
-//   | "iso-8859-8"
-//   | "iso-8859-8-e"
-//   | "iso-ir-138"
-//   | "iso8859-8"
-//   | "iso88598"
-//   | "iso_8859-8"
-//   | "iso_8859-8:1988"
-//   | "visual";
-// type iso_8859_8i = "csiso88598i" | "iso-8859-8-i" | "logical";
-// type iso_8859_10 = "csisolatin6" | "iso-8859-10" | "iso-ir-157" | "iso8859-10" | "iso885910" | "l6" | "latin6";
-// type iso_8859_13 = "iso-8859-13" | "iso8859-13" | "iso885913";
-// type iso_8859_14 = "iso-8859-14" | "iso8859-14" | "iso885914";
-// type iso_8859_15 = "csisolatin9" | "iso-8859-15" | "iso8859-15" | "iso885915" | "l9" | "latin9";
-// type iso_8859_16 = "iso-8859-16";
-// type koi8_r = "cskoi8r" | "koi" | "koi8" | "koi8-r" | "koi8_r";
-// type koi8_u = "koi8-u";
-// type macintosh = "csmacintosh" | "mac" | "macintosh" | "x-mac-roman";
-// type windows_874 = "dos-874" | "iso-8859-11" | "iso8859-11" | "iso885911" | "tis-620" | "windows-874";
-// type windows_1250 = "cp1250" | "windows-1250" | "x-cp1250";
-// type windows_1251 = "cp1251" | "windows-1251" | "x-cp1251";
-// type windows_1252 =
-//   | "ansi_x3.4-1968"
-//   | "ascii"
-//   | "cp1252"
-//   | "cp819"
-//   | "csisolatin1"
-//   | "ibm819"
-//   | "iso-8859-1"
-//   | "iso-ir-100"
-//   | "iso8859-1"
-//   | "iso88591"
-//   | "iso_8859-1"
-//   | "iso_8859-1:1987"
-//   | "l1"
-//   | "latin1"
-//   | "us-ascii"
-//   | "windows-1252"
-//   | "x-cp1252";
-// type windows_1253 = "cp1253" | "windows-1253" | "x-cp1253";
-// type windows_1254 =
-//   | "cp1254"
-//   | "csisolatin5"
-//   | "iso-8859-9"
-//   | "iso-ir-148"
-//   | "iso8859-9"
-//   | "iso88599"
-//   | "iso_8859-9"
-//   | "iso_8859-9:1989"
-//   | "l5"
-//   | "latin5"
-//   | "windows-1254"
-//   | "x-cp1254";
-// type windows_1255 = "cp1255" | "windows-1255" | "x-cp1255";
-// type windows_1256 = "cp1256" | "windows-1256" | "x-cp1256";
-// type windows_1257 = "cp1257" | "windows-1257" | "x-cp1257";
-// type windows_1258 = "cp1258" | "windows-1258" | "x-cp1258";
-// type x_mac_cyrillic = "x-mac-cyrillic" | "x-mac-ukrainian";
-// type gbk =
-//   | "chinese"
-//   | "csgb2312"
-//   | "csiso58gb231280"
-//   | "gb2312"
-//   | "gb_2312"
-//   | "gb_2312-80"
-//   | "gbk"
-//   | "iso-ir-58"
-//   | "x-gbk";
-// type gb18030 = "gb18030";
-// type hz_gb_2312 = "hz-gb-2312";
-// type big5 = "big5" | "big5-hkscs" | "cn-big5" | "csbig5" | "x-x-big5";
-// type euc_jp = "cseucpkdfmtjapanese" | "euc-jp" | "x-euc-jp";
-// type iso_2022_jp = "csiso2022jp" | "iso-2022-jp";
-// type shift_jis = "csshiftjis" | "ms_kanji" | "shift-jis" | "shift_jis" | "sjis" | "windows-31j" | "x-sjis";
-// type euc_kr =
-//   | "cseuckr"
-//   | "csksc56011987"
-//   | "euc-kr"
-//   | "iso-ir-149"
-//   | "korean"
-//   | "ks_c_5601-1987"
-//   | "ks_c_5601-1989"
-//   | "ksc5601"
-//   | "ksc_5601"
-//   | "windows-949";
-// type iso_2022_kr = "csiso2022kr" | "iso-2022-kr";
-// type utf_16be = "utf-16be";
-// type utf_16le = "utf-16" | "utf-16le";
-// type x_user_defined = "x-user-defined";
-// type replacement = "iso-2022-cn" | "iso-2022-cn-ext";
+// Every label the runtime accepts is a valid Bun.Encoding.
+labels satisfies readonly Bun.Encoding[];
 
-// type TextEncoding =
-//   | utf_8
-//   | ibm866
-//   | iso_8859_2
-//   | iso_8859_3
-//   | iso_8859_4
-//   | iso_8859_5
-//   | iso_8859_6
-//   | iso_8859_7
-//   | iso_8859_8
-//   | iso_8859_8i
-//   | iso_8859_10
-//   | iso_8859_13
-//   | iso_8859_14
-//   | iso_8859_15
-//   | iso_8859_16
-//   | koi8_r
-//   | koi8_u
-//   | macintosh
-//   | windows_874
-//   | windows_1250
-//   | windows_1251
-//   | windows_1252
-//   | windows_1253
-//   | windows_1254
-//   | windows_1255
-//   | windows_1256
-//   | windows_1257
-//   | windows_1258
-//   | x_mac_cyrillic
-//   | gbk
-//   | gb18030
-//   | hz_gb_2312
-//   | big5
-//   | euc_jp
-//   | iso_2022_jp
-//   | shift_jis
-//   | euc_kr
-//   | iso_2022_kr
-//   | utf_16be
-//   | utf_16le
-//   | x_user_defined
-//   | replacement;
+// Bun.Encoding contains nothing beyond those labels.
+declare const anyEncoding: Bun.Encoding;
+anyEncoding satisfies (typeof labels)[number];
 
-// export type TextDecoderOptions = ConstructorParameters<typeof TextDecoder>[1];
+for (const label of labels) {
+  new TextDecoder(label);
+}
 
-// function decode(encoding: TextEncoding, array: ArrayBufferView | ArrayBuffer, options?: TextDecoderOptions): string {
-//   const decoder = new TextDecoder(encoding, options);
-//   return decoder.decode(array);
-// }
+new TextDecoder("windows-1251", { fatal: true, ignoreBOM: true }).decode(
+  Uint8Array.from([0xcf, 0xf0, 0xe8, 0xe2, 0xe5, 0xf2]),
+);
 
-// decode("utf-8", new Uint8Array([0x41, 0x42, 0x43]), {
-//   fatal: true,
-// });
+// @ts-expect-error - the TextDecoder constructor rejects the replacement encoding
+"hz-gb-2312" satisfies Bun.Encoding;
+
+// @ts-expect-error - the TextDecoder constructor rejects the replacement encoding
+"replacement" satisfies Bun.Encoding;
+
+// @ts-expect-error - not a label the Encoding Standard defines
+"utf-32" satisfies Bun.Encoding;
+
+new TextEncoder().encode("hello");
 
 export {};