diff --git a/lib/env.ts b/lib/env.ts
index ca9d189..df50c4a 100644
--- a/lib/env.ts
+++ b/lib/env.ts
@@ -1,6 +1,6 @@
 import { fetchPrivateKey, fetchPublicKey } from 'utils';
 
-const appUrl = process.env.APP_URL || 'http://localhost:4000';
+const appUrl = process.env.APP_URL || `https://${process.env.VERCEL_PROJECT_PRODUCTION_URL}` || 'http://localhost:4000';
 const entityId = process.env.ENTITY_ID || 'https://saml.example.com/entityid';
 const privateKey = fetchPrivateKey();
 const publicKey = fetchPublicKey();