diff --git a/src/Form/Model/ParticipantData.php b/src/Form/Model/ParticipantData.php
index e574810..80c4084 100644
--- a/src/Form/Model/ParticipantData.php
+++ b/src/Form/Model/ParticipantData.php
@@ -40,8 +40,13 @@ class ParticipantData
     public array $skiPass = [];
     public array $board = [];
     public array $rentals = [];
+
+    #[Assert\NotNull(message: 'Bitte angeben')]
     public ?Service $transportationServiceTo = null;
+
+    #[Assert\NotNull(message: 'Bitte angeben')]
     public ?Service $transportationServiceFro = null;
+
     public ?Pickup $pickup = null;
 
     #[Assert\Callback]