diff --git a/lib/services/notifications/leantime-adapter.ts b/lib/services/notifications/leantime-adapter.ts
index 176aea80..86c2f776 100644
--- a/lib/services/notifications/leantime-adapter.ts
+++ b/lib/services/notifications/leantime-adapter.ts
@@ -504,8 +504,8 @@ export class LeantimeAdapter implements NotificationAdapter {
       };
       
       // Process notifications in batches
-      const notificationIds = unreadNotifications
-        .map((n: { id: number | string; sourceId: string }) => {
+      const notificationIds: number[] = unreadNotifications
+        .map((n: { id: number | string; sourceId: string }): number | null => {
           const id = typeof n.id === 'number' ? n.id : parseInt(String(n.id || n.sourceId));
           return isNaN(id) ? null : id;
         })