diff --git a/src/http/routes/generate-referral.ts b/src/http/routes/generate-referral.ts
index 9c91912..8e3b969 100644
--- a/src/http/routes/generate-referral.ts
+++ b/src/http/routes/generate-referral.ts
@@ -19,6 +19,9 @@ const responseSchema = {
   400: z.object({
     message: z.string().describe('Error occurred'),
   }),
+  401: z.object({
+    message: z.string().describe('Subscription not found'),
+  }),
   409: z.object({
     message: z.string().describe('Referral already exists'),
   }),