diff --git a/src/lib/payments/polar.ts b/src/lib/payments/polar.ts
index e99c250..e962c09 100644
--- a/src/lib/payments/polar.ts
+++ b/src/lib/payments/polar.ts
@@ -59,7 +59,9 @@ export function verifyPolarWebhook(
 ): boolean {
   if (!WEBHOOK_SECRET) return false;
   try {
-    const wh = new Webhook(WEBHOOK_SECRET);
+    // Svix whsec_ prefix bekler; polar_whs_ → whsec_ dönüşümü
+    const secret = WEBHOOK_SECRET.replace(/^polar_whs_/, "whsec_");
+    const wh = new Webhook(secret);
     wh.verify(rawBody, headers);
     return true;
   } catch {