diff --git a/src/middleware.ts b/src/middleware.ts
index 4528d31..9856100 100644
--- a/src/middleware.ts
+++ b/src/middleware.ts
@@ -28,7 +28,9 @@ async function getRedirects(siteURL: string) {
 }
 
 export async function middleware(request: NextRequest) {
-  const siteURL = process.env['NEXT_PUBLIC_SITE_URL'] ?? 'http://localhost:3000'
+  // Internal self-fetch: must be 127.0.0.1, not localhost — in Docker localhost
+  // resolves to ::1 while Next listens on IPv4 only, so the fetch fails silently.
+  const siteURL = process.env['INTERNAL_API_URL'] ?? 'http://127.0.0.1:3000'
   const pathname = request.nextUrl.pathname
 
   const redirects = await getRedirects(siteURL)