diff --git a/cli/tests/unit_node/querystring_test.ts b/cli/tests/unit_node/querystring_test.ts
index d750bed950..ce2747db2b 100644
--- a/cli/tests/unit_node/querystring_test.ts
+++ b/cli/tests/unit_node/querystring_test.ts
@@ -28,3 +28,24 @@ Deno.test({
     });
   },
 });
+
+// https://github.com/denoland/deno/issues/21734
+Deno.test({
+  name: "stringify options no encode",
+  fn() {
+    assertEquals(
+      stringify(
+        {
+          a: "hello",
+          b: 5,
+          c: true,
+          d: ["foo", "bar"],
+        },
+        "&",
+        "=",
+        {},
+      ),
+      "a=hello&b=5&c=true&d=foo&d=bar",
+    );
+  },
+});
diff --git a/ext/node/lib.rs b/ext/node/lib.rs
index ac35f8f26b..2aac49754d 100644
--- a/ext/node/lib.rs
+++ b/ext/node/lib.rs
@@ -523,7 +523,7 @@ deno_core::extension!(deno_node,
     "perf_hooks.ts" with_specifier "node:perf_hooks",
     "process.ts" with_specifier "node:process",
     "punycode.ts" with_specifier "node:punycode",
-    "querystring.ts" with_specifier "node:querystring",
+    "querystring.js" with_specifier "node:querystring",
     "readline.ts" with_specifier "node:readline",
     "repl.ts" with_specifier "node:repl",
     "stream.ts" with_specifier "node:stream",
diff --git a/ext/node/polyfills/querystring.ts b/ext/node/polyfills/querystring.js
similarity index 87%
rename from ext/node/polyfills/querystring.ts
rename to ext/node/polyfills/querystring.js
index 14bc3ea23d..5eb6a077aa 100644
--- a/ext/node/polyfills/querystring.ts
+++ b/ext/node/polyfills/querystring.js
@@ -22,7 +22,7 @@ export const encode = stringify;
  * replaces encodeURIComponent()
  * @see https://www.ecma-international.org/ecma-262/5.1/#sec-15.1.3.4
  */
-function qsEscape(str: unknown): string {
+function qsEscape(str) {
   if (typeof str !== "string") {
     if (typeof str === "object") {
       str = String(str);
@@ -30,7 +30,7 @@ function qsEscape(str: unknown): string {
       str += "";
     }
   }
-  return encodeStr(str as string, noEscape, hexTable);
+  return encodeStr(str, noEscape, hexTable);
 }
 
 /**
@@ -42,29 +42,6 @@ function qsEscape(str: unknown): string {
  */
 export const escape = qsEscape;
 
-export interface ParsedUrlQuery {
-  [key: string]: string | string[] | undefined;
-}
-
-export interface ParsedUrlQueryInput {
-  [key: string]:
-    | string
-    | number
-    | boolean
-    | ReadonlyArray<string>
-    | ReadonlyArray<number>
-    | ReadonlyArray<boolean>
-    | null
-    | undefined;
-}
-
-interface ParseOptions {
-  /** The function to use when decoding percent-encoded characters in the query string. */
-  decodeURIComponent?: (string: string) => string;
-  /** Specifies the maximum number of keys to parse. */
-  maxKeys?: number;
-}
-
 // deno-fmt-ignore
 const isHexTable = new Int8Array([
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0 - 15
@@ -85,7 +62,7 @@ const isHexTable = new Int8Array([
   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  // ... 256
 ]);
 
-function charCodes(str: string): number[] {
+function charCodes(str) {
   const ret = new Array(str.length);
   for (let i = 0; i < str.length; ++i) {
     ret[i] = str.charCodeAt(i);
@@ -94,12 +71,12 @@ function charCodes(str: string): number[] {
 }
 
 function addKeyVal(
-  obj: ParsedUrlQuery,
-  key: string,
-  value: string,
-  keyEncoded: boolean,
-  valEncoded: boolean,
-  decode: (encodedURIComponent: string) => string,
+  obj,
+  key,
+  value,
+  keyEncoded,
+  valEncoded,
+  decode,
 ) {
   if (key.length > 0 && keyEncoded) {
     key = decode(key);
@@ -115,10 +92,10 @@ function addKeyVal(
     // A simple Array-specific property check is enough here to
     // distinguish from a string value and is faster and still safe
     // since we are generating all of the values being assigned.
-    if ((curValue as string[]).pop) {
-      (curValue as string[])[curValue!.length] = value;
+    if (curValue.pop) {
+      curValue[curValue.length] = value;
     } else {
-      obj[key] = [curValue as string, value];
+      obj[key] = [curValue, value];
     }
   }
 }
@@ -135,12 +112,12 @@ function addKeyVal(
  * @see Tested in test-querystring.js
  */
 export function parse(
-  str: string,
+  str,
   sep = "&",
   eq = "=",
-  { decodeURIComponent = unescape, maxKeys = 1000 }: ParseOptions = {},
-): ParsedUrlQuery {
-  const obj: ParsedUrlQuery = Object.create(null);
+  { decodeURIComponent = unescape, maxKeys = 1000 } = {},
+) {
+  const obj = Object.create(null);
 
   if (typeof str !== "string" || str.length === 0) {
     return obj;
@@ -298,11 +275,6 @@ export function parse(
   return obj;
 }
 
-interface StringifyOptions {
-  /** The function to use when converting URL-unsafe characters to percent-encoding in the query string. */
-  encodeURIComponent: (string: string) => string;
-}
-
 /**
  * These characters do not need escaping when generating query strings:
  * ! - . _ ~
@@ -323,8 +295,7 @@ const noEscape = new Int8Array([
   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0,  // 112 - 127
 ]);
 
-// deno-lint-ignore no-explicit-any
-function stringifyPrimitive(v: any): string {
+function stringifyPrimitive(v) {
   if (typeof v === "string") {
     return v;
   }
@@ -341,15 +312,13 @@ function stringifyPrimitive(v: any): string {
 }
 
 function encodeStringifiedCustom(
-  // deno-lint-ignore no-explicit-any
-  v: any,
-  encode: (string: string) => string,
-): string {
+  v,
+  encode,
+) {
   return encode(stringifyPrimitive(v));
 }
 
-// deno-lint-ignore no-explicit-any
-function encodeStringified(v: any, encode: (string: string) => string): string {
+function encodeStringified(v, encode) {
   if (typeof v === "string") {
     return (v.length ? encode(v) : "");
   }
@@ -378,15 +347,14 @@ function encodeStringified(v: any, encode: (string: string) => string): string {
  * @see Tested in `test-querystring.js`
  */
 export function stringify(
-  // deno-lint-ignore no-explicit-any
-  obj: Record<string, any>,
-  sep?: string,
-  eq?: string,
-  options?: StringifyOptions,
-): string {
+  obj,
+  sep,
+  eq,
+  options,
+) {
   sep ||= "&";
   eq ||= "=";
-  const encode = options ? options.encodeURIComponent : qsEscape;
+  const encode = options ? (options.encodeURIComponent || qsEscape) : qsEscape;
   const convert = options ? encodeStringifiedCustom : encodeStringified;
 
   if (obj !== null && typeof obj === "object") {
@@ -448,7 +416,7 @@ const unhexTable = new Int8Array([
 /**
  * A safe fast alternative to decodeURIComponent
  */
-export function unescapeBuffer(s: string, decodeSpaces = false): Buffer {
+export function unescapeBuffer(s, decodeSpaces = false) {
   const out = Buffer.alloc(s.length);
   let index = 0;
   let outIndex = 0;
@@ -490,7 +458,7 @@ export function unescapeBuffer(s: string, decodeSpaces = false): Buffer {
   return hasHex ? out.slice(0, outIndex) : out;
 }
 
-function qsUnescape(s: string): string {
+function qsUnescape(s) {
   try {
     return decodeURIComponent(s);
   } catch {
diff --git a/tools/core_import_map.json b/tools/core_import_map.json
index 6dff4c9306..8122a2c84d 100644
--- a/tools/core_import_map.json
+++ b/tools/core_import_map.json
@@ -181,7 +181,7 @@
     "node:perf_hooks": "../ext/node/polyfills/perf_hooks.ts",
     "node:process": "../ext/node/polyfills/process.ts",
     "node:punycode": "../ext/node/polyfills/punycode.ts",
-    "node:querystring": "../ext/node/polyfills/querystring.ts",
+    "node:querystring": "../ext/node/polyfills/querystring.js",
     "node:readline": "../ext/node/polyfills/readline.ts",
     "ext:deno_node/readline/promises.ts": "../ext/node/polyfills/readline/promises.ts",
     "ext:deno_node/repl.ts": "../ext/node/polyfills/repl.ts",