diff --git a/types/index.d.ts b/types/index.d.ts
index 6a8fb272..cc8d002b 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -18,6 +18,7 @@ import {
   IncomingMessage,
   RequestOptions,
 } from 'node:http'
+import { Readable } from 'node:stream'
 import {
   ClientSessionOptions,
   ClientSessionRequestOptions,
@@ -66,6 +67,12 @@ declare namespace fastifyReplyFrom {
     stream: IncomingMessage
   }
 
+  export interface FastifyReplyFromResponse {
+    statusCode: number
+    headers: IncomingHttpHeaders | Http2IncomingHttpHeaders
+    stream: Readable
+  }
+
   export interface FastifyReplyFromHooks {
     queryString?: { [key: string]: unknown } | QueryStringFunction;
     contentType?: string;
@@ -74,7 +81,7 @@ declare namespace fastifyReplyFrom {
     onResponse?: (
       request: FastifyRequest<RequestGenericInterface, RawServerBase>,
       reply: FastifyReply<RouteGenericInterface, RawServerBase>,
-      res: RawServerResponse<RawServerBase>
+      res: FastifyReplyFromResponse
     ) => void;
     onError?: (
       reply: FastifyReply<RouteGenericInterface, RawServerBase>,
diff --git a/types/index.tst.ts b/types/index.tst.ts
index 5e2bf6f8..c77db3ac 100644
--- a/types/index.tst.ts
+++ b/types/index.tst.ts
@@ -12,8 +12,11 @@ import * as https from 'node:https'
 import { Agent, Client, Dispatcher, Pool } from 'undici'
 import replyFrom, {
   type FastifyReplyFromOptions,
+  type FastifyReplyFromResponse,
   type RawServerResponse
 } from '.'
+import { type IncomingHttpHeaders as Http1IncomingHttpHeaders } from 'node:http'
+import { type Readable } from 'node:stream'
 
 const fullOptions: FastifyReplyFromOptions = {
   base: 'http://example2.com',
@@ -83,8 +86,11 @@ app.get('/v3', (_request, reply) => {
     onResponse (request, reply, res) {
       expect(request).type.toBe<FastifyRequest<RequestGenericInterface, RawServerBase>>()
       expect(reply).type.toBe<FastifyReply<RouteGenericInterface, RawServerBase>>()
-      expect(res).type.toBe<RawServerResponse<RawServerBase>>()
+      expect(res).type.toBe<FastifyReplyFromResponse>()
       expect(res.statusCode).type.toBe<number>()
+      expect(res.headers).type.toBe<Http1IncomingHttpHeaders | IncomingHttpHeaders>()
+      expect(res.stream).type.toBe<Readable>()
+      expect<RawServerResponse<RawServerBase>>().type.toBe<RawServerResponse<RawServerBase>>()
     }
   })
 })