diff --git a/app/api/create-checkout-session/route.ts b/app/api/create-checkout-session/route.ts
index 6b0ae78..b19f929 100644
--- a/app/api/create-checkout-session/route.ts
+++ b/app/api/create-checkout-session/route.ts
@@ -8,6 +8,9 @@ const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!, {
 // Dynamic pricing configuration (in EUR cents)
 const TICKET_PRICE_CENTS = 8000 // €80 early bird
 
+// Public base URL (needed because request.nextUrl.origin returns internal Docker address)
+const BASE_URL = process.env.NEXT_PUBLIC_BASE_URL || "https://cryptocommonsgather.ing"
+
 export async function POST(request: NextRequest) {
   try {
     const formData = await request.formData()
@@ -43,8 +46,8 @@ export async function POST(request: NextRequest) {
       payment_method_types: paymentMethodTypes,
       line_items: lineItems,
       mode: "payment",
-      success_url: `${request.nextUrl.origin}/success?session_id={CHECKOUT_SESSION_ID}`,
-      cancel_url: `${request.nextUrl.origin}/register`,
+      success_url: `${BASE_URL}/success?session_id={CHECKOUT_SESSION_ID}`,
+      cancel_url: `${BASE_URL}/register`,
       metadata: registrationData
         ? {
             name: registrationData.name,