diff --git a/package.json b/package.json
index 8d7581c8..6c488060 100644
--- a/package.json
+++ b/package.json
@@ -76,7 +76,6 @@
     "mime-types": "^2.1.35",
     "pump": "^3.0.0",
     "qs": "^6.11.2",
-    "type-fest": "^4.3.1",
     "undici": "^5.22.1",
     "ylru": "^1.3.2"
   },
diff --git a/src/HttpClient.ts b/src/HttpClient.ts
index de69ebf3..de021c57 100644
--- a/src/HttpClient.ts
+++ b/src/HttpClient.ts
@@ -39,8 +39,6 @@ import { initDiagnosticsChannel } from './diagnosticsChannel.js';
 
 type Exists<T> = T extends undefined ? never : T;
 type UndiciRequestOption = Exists<Parameters<typeof undiciRequest>[1]>;
-type PropertyShouldBe<T, K extends keyof T, V> = Omit<T, K> & { [P in K]: V };
-type IUndiciRequestOption = PropertyShouldBe<UndiciRequestOption, 'headers', IncomingHttpHeaders>;
 
 const PROTO_RE = /^https?:\/\//i;
 const FormData = FormDataNative ?? FormDataNode;
@@ -347,7 +345,7 @@ export class HttpClient extends EventEmitter {
     }
 
     try {
-      const requestOptions: IUndiciRequestOption = {
+      const requestOptions: UndiciRequestOption = {
         method,
         maxRedirections: args.maxRedirects ?? 10,
         headersTimeout,
diff --git a/src/IncomingHttpHeaders.ts b/src/IncomingHttpHeaders.ts
index adc42aac..9407f682 100644
--- a/src/IncomingHttpHeaders.ts
+++ b/src/IncomingHttpHeaders.ts
@@ -1,7 +1,3 @@
-import type { Except } from 'type-fest';
-import type { IncomingHttpHeaders as HTTPIncomingHttpHeaders } from 'node:http';
-
 // fix set-cookie type define https://github.com/nodejs/undici/pull/1893
-export interface IncomingHttpHeaders extends Except<HTTPIncomingHttpHeaders, 'set-cookie'> {
-  'set-cookie'?: string | string[];
-}
+// keep the same type as undici IncomingHttpHeaders
+export type IncomingHttpHeaders = Record<string, string | string[] | undefined>;