diff --git a/src/prepare-split-challenge.spec.ts b/src/prepare-split-challenge.spec.ts
index a6b8f81..7081c24 100644
--- a/src/prepare-split-challenge.spec.ts
+++ b/src/prepare-split-challenge.spec.ts
@@ -1,7 +1,6 @@
 import { prepareSplitChallenge } from './prepare-split-challenge'
 import { writeFileSync, existsSync, mkdirSync } from 'fs'
 import { findPagesDir } from 'next/dist/lib/find-pages-dir'
-import { SplitOptions } from './types'
 
 jest.mock('fs', () => ({
   writeFileSync: jest.fn(),
@@ -14,10 +13,11 @@ jest.mock('next/dist/lib/find-pages-dir', () => ({
 }))
 
 jest.spyOn(console, 'error').mockImplementation((mes) => console.log(mes))
-// eslint-disable-next-line @typescript-eslint/ban-ts-comment
-// @ts-ignore
+
 const mockExit = jest
   .spyOn(process, 'exit')
+  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+  // @ts-ignore
   .mockImplementation((code) => console.log('exit: ', code))
 
 describe('prepareSplitChallenge', () => {
@@ -34,7 +34,7 @@ describe('prepareSplitChallenge', () => {
     process.env = { ...process.env, VERCEL_ENV: 'production' }
     ;(findPagesDir as jest.Mock).mockReturnValue('pages')
     ;(existsSync as jest.Mock).mockReturnValue(false)
-    prepareSplitChallenge({})
+    prepareSplitChallenge()
     expect(mkdirSync).toBeCalled()
     expect(writeFileSync).toBeCalledWith(
       'pages/_split-challenge/[__key].js',
@@ -48,16 +48,16 @@ export default SplitChallenge
     process.env = { ...process.env, VERCEL_ENV: 'production' }
     ;(findPagesDir as jest.Mock).mockReturnValue('pages')
     ;(existsSync as jest.Mock).mockReturnValue(true)
-    prepareSplitChallenge({})
+    prepareSplitChallenge()
     expect(mkdirSync).not.toBeCalled()
   })
   it('must not work when runs on not production', () => {
-    prepareSplitChallenge({})
+    prepareSplitChallenge()
     expect(writeFileSync).not.toBeCalled()
   })
   it('must not work when challenge file is existing', () => {
     process.env = { ...process.env, VERCEL_ENV: 'production' }
-    prepareSplitChallenge({ challengeFileExisting: true } as SplitOptions)
+    prepareSplitChallenge(true)
     expect(writeFileSync).not.toBeCalled()
   })
   it('must request a self-creation when an exception is raised', () => {
@@ -65,7 +65,7 @@ export default SplitChallenge
     ;(findPagesDir as jest.Mock).mockImplementation(() => {
       throw new Error('some error.')
     })
-    prepareSplitChallenge({})
+    prepareSplitChallenge()
     expect(writeFileSync).not.toBeCalled()
     expect(mockExit).toBeCalledWith(1)
   })
diff --git a/src/prepare-split-challenge.ts b/src/prepare-split-challenge.ts
index f53b58d..d69d21f 100644
--- a/src/prepare-split-challenge.ts
+++ b/src/prepare-split-challenge.ts
@@ -1,15 +1,15 @@
 import { findPagesDir } from 'next/dist/lib/find-pages-dir'
 import { writeFileSync, existsSync, mkdirSync } from 'fs'
-import { SplitOptions } from './types'
 
 const scriptText = `export { getServerSideProps } from 'next-with-split'
 const SplitChallenge = () => null
 export default SplitChallenge
 `
 
-export const prepareSplitChallenge = (options: SplitOptions): void => {
-  if (process.env.VERCEL_ENV !== 'production' || options.challengeFileExisting)
-    return
+export const prepareSplitChallenge = (
+  challengeFileExisting?: boolean
+): void => {
+  if (process.env.VERCEL_ENV !== 'production' || challengeFileExisting) return
   try {
     const dir = `${findPagesDir('')}/_split-challenge`
     if (!existsSync(dir)) mkdirSync(dir, { recursive: true })
@@ -17,7 +17,7 @@ export const prepareSplitChallenge = (options: SplitOptions): void => {
   } catch (e) {
     console.error(e.message)
     console.log(`> Could not create the necessary file for the split test.
-Create the file yourself and set \`splits.challengeFileExisting: true\`.
+Create the file yourself and set \`challengeFileExisting: true\`.
 The code in the file should look like this
 // pages/_split-challenge/[__key].js
 ${scriptText}`)
diff --git a/src/split-challenge.ts b/src/split-challenge.ts
index c83bf81..9e9b937 100644
--- a/src/split-challenge.ts
+++ b/src/split-challenge.ts
@@ -39,7 +39,7 @@ export const sticky = (
 ): ReturnType<typeof setCookie> =>
   setCookie(ctx, cookieKey(splitKey), config.branch, config.cookie)
 
-export const getPath = (config: SplitConfig, query: ParsedUrlQuery) => {
+export const getPath = (config: SplitConfig, query: ParsedUrlQuery): string => {
   const keys: {
     name: string
     prefix: string
diff --git a/src/types.d.ts b/src/types.d.ts
index 51eb44f..0a4f1f4 100644
--- a/src/types.d.ts
+++ b/src/types.d.ts
@@ -10,7 +10,6 @@ export type Rewrites =
   | Rewrite[]
 
 export type SplitOptions = {
-  challengeFileExisting?: boolean
   [keyName: string]: {
     path: string
     hosts: {
diff --git a/src/with-split.spec.ts b/src/with-split.spec.ts
index d895f33..50df496 100644
--- a/src/with-split.spec.ts
+++ b/src/with-split.spec.ts
@@ -104,6 +104,51 @@ describe('withSplit', () => {
       })
     })
   })
+  it('return split test config when challenge file existing', () => {
+    process.env = {
+      ...process.env,
+      VERCEL_URL: 'vercel.example.com',
+      VERCEL_ENV: 'production'
+    }
+    const conf = withSplit({
+      splits: {
+        test1: {
+          hosts: {
+            branch1: 'https://branch1.example.com',
+            branch2: 'https://branch2.example.com'
+          },
+          path: '/foo/:path*'
+        }
+      },
+      challengeFileExisting: true
+    })
+    expect(conf.serverRuntimeConfig).toEqual({
+      splits: {
+        test1: {
+          branch1: {
+            host: 'https://branch1.example.com',
+            path: '/foo/:path*',
+            cookie: { path: '/', maxAge: 60 * 60 * 24 }
+          },
+          branch2: {
+            host: 'https://branch2.example.com',
+            path: '/foo/:path*',
+            cookie: { path: '/', maxAge: 60 * 60 * 24 }
+          }
+        }
+      }
+    })
+    return conf.rewrites().then((res) => {
+      expect(res).toEqual({
+        beforeFiles: [
+          {
+            source: '/foo/:path*',
+            destination: '/_split-challenge/test1'
+          }
+        ]
+      })
+    })
+  })
   it('return empty rewrite rules when runs on not production', () => {
     process.env = { ...process.env, VERCEL_ENV: 'preview' }
     const conf = withSplit({
diff --git a/src/with-split.ts b/src/with-split.ts
index 05221c2..ad22c1a 100644
--- a/src/with-split.ts
+++ b/src/with-split.ts
@@ -5,6 +5,7 @@ import { makeRuntimeConfig } from './makeRuntimeConfig'
 
 type WithSplitArgs = {
   splits?: SplitOptions
+  challengeFileExisting?: boolean
   rewrites?: () => Promise<Rewrites>
   assetPrefix?: string
   serverRuntimeConfig?: {
@@ -22,7 +23,7 @@ type WithSplitResult = Omit<Required<WithSplitArgs>, 'splits'> & {
 }
 
 export const withSplit = (args: WithSplitArgs): WithSplitResult => {
-  const { splits = {}, ...nextConfig } = args
+  const { splits = {}, challengeFileExisting, ...nextConfig } = args
 
   if (
     Object.keys(splits).length > 0 &&
@@ -38,7 +39,7 @@ export const withSplit = (args: WithSplitArgs): WithSplitResult => {
     )
   }
 
-  prepareSplitChallenge(splits)
+  prepareSplitChallenge(challengeFileExisting)
 
   return {
     ...nextConfig,