diff --git a/packages/next/client/index.js b/packages/next/client/index.js
index fc7d439a8a5f4..4292764b202ec 100644
--- a/packages/next/client/index.js
+++ b/packages/next/client/index.js
@@ -9,7 +9,7 @@ import { RouterContext } from '../next-server/lib/router-context'
 import { isDynamicRoute } from '../next-server/lib/router/utils/is-dynamic'
 import * as envConfig from '../next-server/lib/runtime-config'
 import { getURL, loadGetInitialProps, ST } from '../next-server/lib/utils'
-import { delBasePath } from '../next-server/lib/router/router'
+import { delBasePath, basePath } from '../next-server/lib/router/router'
 import initHeadManager from './head-manager'
 import PageLoader from './page-loader'
 import measureWebVitals from './performance-relayer'
@@ -52,15 +52,7 @@ envConfig.setConfig({
 let asPath = getURL()
 
 // make sure not to attempt stripping basePath for 404s
-if (
-  page !== '/404' &&
-  !(
-    page === '/_error' &&
-    hydrateProps &&
-    hydrateProps.pageProps &&
-    hydrateProps.pageProps.statusCode === 404
-  )
-) {
+if (asPath.startsWith(basePath)) {
   asPath = delBasePath(asPath)
 }
 
diff --git a/packages/next/next-server/lib/router/router.ts b/packages/next/next-server/lib/router/router.ts
index a55631b2100cf..538db7544ff6b 100644
--- a/packages/next/next-server/lib/router/router.ts
+++ b/packages/next/next-server/lib/router/router.ts
@@ -22,7 +22,7 @@ import {
   normalizePathTrailingSlash,
 } from '../../../client/normalize-trailing-slash'
 
-const basePath = (process.env.__NEXT_ROUTER_BASEPATH as string) || ''
+export const basePath = (process.env.__NEXT_ROUTER_BASEPATH as string) || ''
 
 function buildCancellationError() {
   return Object.assign(new Error('Route Cancelled'), {