diff --git a/packages/next/src/client/app-find-source-map-url.ts b/packages/next/src/client/app-find-source-map-url.ts
index 7b2006e703322..b143c755568b7 100644
--- a/packages/next/src/client/app-find-source-map-url.ts
+++ b/packages/next/src/client/app-find-source-map-url.ts
@@ -8,7 +8,10 @@ export const findSourceMapURL =
 
         url.searchParams.set(
           'filename',
-          filename.replace(new RegExp(`^${document.location.origin}`), '')
+          filename.replace(
+            new RegExp(`^${document.location.origin}${basePath}`),
+            ''
+          )
         )
 
         return url.href