diff --git a/test/fetch/createFetchMock.ts b/test/fetch/createFetchMock.ts
index 3d74eb8..4e4daa4 100644
--- a/test/fetch/createFetchMock.ts
+++ b/test/fetch/createFetchMock.ts
@@ -3,13 +3,17 @@ import {type MockedResponse} from '@Test/fetch/defineMockResponse';
 import {getAutoImplementation} from './getAutoImplementation';
 
 export const createFetchMock = <T>(
-  implementation?: MockedResponse<T>,
+  implementation?: MockedResponse<T> | (() => Promise<MockedResponse<T>>),
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   options?: Record<string, unknown>,
 ): FetchMock => {
   return fetchMock.mockImplementation(async (info, init) => {
     let resolvedImplementation = implementation;
 
+    if (typeof implementation === 'function') {
+      resolvedImplementation = await implementation();
+    }
+
     if (!implementation && info) {
       resolvedImplementation = await getAutoImplementation(info, init);
     }
diff --git a/test/fetch/defineMockResponse.ts b/test/fetch/defineMockResponse.ts
index ebf03f4..39e738a 100644
--- a/test/fetch/defineMockResponse.ts
+++ b/test/fetch/defineMockResponse.ts
@@ -10,7 +10,7 @@ export interface MockedResponse<E = unknown> extends ResponseInit {
 
 export interface MockResponse<E> {
   match(url: string, init?: RequestInit): boolean;
-  response(): MockedResponse<E>;
+  response(): MockedResponse<E> | Promise<MockedResponse<E>>;
 }
 
 export const defineMockResponse = <E>(responseObject: MockResponse<E>): MockResponse<E> => {
diff --git a/test/fetch/examples/get-extended-timeout.ts b/test/fetch/examples/get-extended-timeout.ts
index b5d1227..6134d40 100644
--- a/test/fetch/examples/get-extended-timeout.ts
+++ b/test/fetch/examples/get-extended-timeout.ts
@@ -1,12 +1,12 @@
 // noinspection JSUnusedGlobalSymbols
 
-import {defineMockResponse} from '@Test/fetch/defineMockResponse';
+import {type MockedResponse, defineMockResponse} from '@Test/fetch/defineMockResponse';
 
 export default defineMockResponse({
   match: (path: string, init?: RequestInit) => init?.method === 'GET' && path === '/timeout',
 
   response: () => {
-    return new Promise((resolve) => {
+    return new Promise<MockedResponse>((resolve) => {
       setTimeout(() => {
         resolve({
           headers: {'Content-Type': 'application/json'},