diff --git a/app/Notifications/UploadPo.php b/app/Notifications/UploadPo.php
index 043bb893..0cbb39a6 100644
--- a/app/Notifications/UploadPo.php
+++ b/app/Notifications/UploadPo.php
@@ -22,6 +22,11 @@ class UploadPo extends Notification
         $this->booking = $booking;
     }
 
+    public function via()
+    {
+        return 'mail';
+    }
+
 
     /**
      * Build the mail representation of the notification.