diff --git a/package.json b/package.json
index 2ff4bf9e..9d5f6881 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "media-streamer",
-  "version": "0.6.0",
+  "version": "0.6.1",
   "private": true,
   "type": "module",
   "scripts": {
diff --git a/src/app/i/[code]/route.test.ts b/src/app/i/[code]/route.test.ts
index 7bd20803..683b3b62 100644
--- a/src/app/i/[code]/route.test.ts
+++ b/src/app/i/[code]/route.test.ts
@@ -22,6 +22,14 @@ describe('/i/<code>', () => {
     );
   });
 
+  it('answers with the public host, not the container address behind nginx', async () => {
+    const res = await GET(
+      new NextRequest('http://localhost:3000/i/ABCDEFGHJK', { headers: { host: 'bittorrented.com' } }),
+      { params: Promise.resolve({ code: 'ABCDEFGHJK' }) }
+    );
+    expect(res.headers.get('location')).toBe('https://bittorrented.com/signup?invite=ABCDE-FGHJK');
+  });
+
   it('sends a malformed code to the invite-only screen', async () => {
     expect((await go('/i/nope')).location).toBe('https://bittorrented.com/invite-only');
   });
diff --git a/src/app/i/[code]/route.ts b/src/app/i/[code]/route.ts
index d42ec385..6494c80a 100644
--- a/src/app/i/[code]/route.ts
+++ b/src/app/i/[code]/route.ts
@@ -12,10 +12,17 @@ import { formatInviteCode, isInviteCodeShape, normalizeInviteCode } from '@/lib/
 
 export const dynamic = 'force-dynamic';
 
+/** The public origin: behind nginx, request.url is the container's localhost:3000. */
+function origin(request: NextRequest): string {
+  const host = request.headers.get('x-forwarded-host') ?? request.headers.get('host') ?? request.nextUrl.host;
+  const proto = host.startsWith('localhost') || host.startsWith('127.') ? 'http' : 'https';
+  return `${proto}://${host}`;
+}
+
 export async function GET(request: NextRequest, { params }: { params: Promise<{ code: string }> }): Promise<NextResponse> {
   const { code: raw } = await params;
   const code = normalizeInviteCode(decodeURIComponent(raw ?? ''));
-  const target = new URL(isInviteCodeShape(code) ? '/signup' : '/invite-only', request.url);
+  const target = new URL(isInviteCodeShape(code) ? '/signup' : '/invite-only', origin(request));
   if (isInviteCodeShape(code)) target.searchParams.set('invite', formatInviteCode(code));
   const ref = request.nextUrl.searchParams.get('ref');
   if (ref && /^[a-zA-Z0-9_-]{1,64}$/.test(ref)) target.searchParams.set('ref', ref);