diff --git a/web/src/app/api/auth/sign-in/route.ts b/web/src/app/api/auth/sign-in/route.ts
index 561c10b..5563e48 100644
--- a/web/src/app/api/auth/sign-in/route.ts
+++ b/web/src/app/api/auth/sign-in/route.ts
@@ -17,7 +17,7 @@ export async function POST(request: Request) {
   });
 
   const verifyResult = await appClient.verifySignInMessage({
-    domain: 'localhost:3000',
+    domain: process.env.SIWF_DOMAIN || "localhost:3000",
     message,
     nonce,
     signature,