diff --git a/server/index.js b/server/index.js
index 94db1fd..4fb7abf 100644
--- a/server/index.js
+++ b/server/index.js
@@ -1318,8 +1318,10 @@ const server = http.createServer(async (req, res) => {
         const o = olay.data?.object || {};
         switch (olay.type) {
           case 'checkout.session.completed': {
-            const email = (o.client_reference_id || o.customer_email || o.metadata?.email || '').toLowerCase();
-            const planId = o.metadata?.planId || 'pro';
+            const rawEmail = o.client_reference_id || o.customer_email || o.metadata?.email || '';
+            const email = typeof rawEmail === 'string' ? rawEmail.trim().toLowerCase() : '';
+            const rawPlanId = o.metadata?.planId;
+            const planId = typeof rawPlanId === 'string' && rawPlanId.trim() ? rawPlanId.trim() : 'pro';
             if (email) {
               store.setPlan(email, {
                 plan: planId, kaynak: 'stripe',