diff --git a/package-lock.json b/package-lock.json
index 762469f5..aa5a046d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13,7 +13,6 @@
         "debug": "^4.3.4",
         "decompress-response": "^7.0.0",
         "follow-redirects": "^1.15.2",
-        "form-urlencoded": "^6.1.0",
         "into-stream": "^6.0.0",
         "is-plain-object": "^5.0.0",
         "is-retry-allowed": "^2.2.0",
@@ -6975,11 +6974,6 @@
         "node": ">=8.0.0"
       }
     },
-    "node_modules/form-urlencoded": {
-      "version": "6.1.0",
-      "resolved": "https://registry.npmjs.org/form-urlencoded/-/form-urlencoded-6.1.0.tgz",
-      "integrity": "sha512-lc1Qd9nnEewXKoiPjIA1n38M5STbyY6krgoegsg7SsAt2b98HZKe25KaJvKFBwQaOcmh8FP7JbXVC7gocZw+XQ=="
-    },
     "node_modules/from2": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/from2/-/from2-2.3.0.tgz",
diff --git a/package.json b/package.json
index f0abe649..7b195153 100644
--- a/package.json
+++ b/package.json
@@ -100,7 +100,6 @@
     "debug": "^4.3.4",
     "decompress-response": "^7.0.0",
     "follow-redirects": "^1.15.2",
-    "form-urlencoded": "^6.1.0",
     "into-stream": "^6.0.0",
     "is-plain-object": "^5.0.0",
     "is-retry-allowed": "^2.2.0",
diff --git a/src/middleware/urlEncoded.ts b/src/middleware/urlEncoded.ts
index cac26854..0547aa15 100644
--- a/src/middleware/urlEncoded.ts
+++ b/src/middleware/urlEncoded.ts
@@ -1,10 +1,35 @@
-import encode from 'form-urlencoded'
 import {isPlainObject} from 'is-plain-object'
 
-const isBuffer = (obj: any) =>
-  !!obj.constructor &&
-  typeof obj.constructor.isBuffer === 'function' &&
-  obj.constructor.isBuffer(obj)
+import {isBuffer} from '../util/isBuffer'
+
+function encode(data: Record<string, string | Set<number | string>>): string {
+  const query = new URLSearchParams()
+
+  const nest = (name: string, _value: unknown) => {
+    const value = _value instanceof Set ? Array.from(_value) : _value
+    if (Array.isArray(value)) {
+      if (value.length) {
+        for (const index in value) {
+          nest(`${name}[${index}]`, value[index])
+        }
+      } else {
+        query.append(`${name}[]`, '')
+      }
+    } else if (typeof value === 'object' && value !== null) {
+      for (const [key, obj] of Object.entries(value)) {
+        nest(`${name}[${key}]`, obj)
+      }
+    } else {
+      query.append(name, value as string)
+    }
+  }
+
+  for (const [key, value] of Object.entries(data)) {
+    nest(key, value)
+  }
+
+  return query.toString()
+}
 
 /** @public */
 export function urlEncoded(): any {
@@ -22,12 +47,14 @@ export function urlEncoded(): any {
         return options
       }
 
-      return Object.assign({}, options, {
+      return {
+        ...options,
         body: encode(options.body),
-        headers: Object.assign({}, options.headers, {
+        headers: {
+          ...options.headers,
           'Content-Type': 'application/x-www-form-urlencoded',
-        }),
-      })
+        },
+      }
     },
   }
 }
diff --git a/test-deno/import_map.json b/test-deno/import_map.json
index ad6d6c46..a4b01301 100644
--- a/test-deno/import_map.json
+++ b/test-deno/import_map.json
@@ -2,7 +2,6 @@
   "imports": {
     "create-error-class": "https://esm.sh/create-error-class@^3.0.2",
     "debug": "https://esm.sh/debug@^4.3.4",
-    "form-urlencoded": "https://esm.sh/form-urlencoded@^6.1.0",
     "is-plain-object": "https://esm.sh/is-plain-object@^5.0.0",
     "parse-headers": "https://esm.sh/parse-headers@^2.0.5"
   }
diff --git a/test/urlEncoded.test.ts b/test/urlEncoded.test.ts
index 5c35a79b..1a60b92e 100644
--- a/test/urlEncoded.test.ts
+++ b/test/urlEncoded.test.ts
@@ -55,7 +55,8 @@ describe('urlEncoded middleware', () => {
       'obj[prop2][0]': 'elem',
       str: 'val',
       emoji: '😀',
-      set: '1,two',
+      'set[0]': '1',
+      'set[1]': 'two',
     })
   })