diff --git a/src/Form/Model/BookingCreateDto.php b/src/Form/Model/BookingCreateDto.php
index d2626b2..3a5265a 100644
--- a/src/Form/Model/BookingCreateDto.php
+++ b/src/Form/Model/BookingCreateDto.php
@@ -4,6 +4,7 @@ namespace App\Form\Model;
 
 use App\BusProNet\Model\Travel;
 use Symfony\Component\Validator\Constraints as Assert;
+use Symfony\Component\Validator\Context\ExecutionContextInterface;
 
 class BookingCreateDto implements BookingDtoInterface
 {
@@ -49,4 +50,15 @@ class BookingCreateDto implements BookingDtoInterface
     {
         return $this->participants[$index] ?? null;
     }
+
+    #[Assert\Callback(callback: 'validateRoomSelection', groups: ['booking_create_step_1'])]
+    public function validateRoomSelection(ExecutionContextInterface $context): void
+    {
+        $selectedRooms = $this->getSelectedRooms();
+
+        if (0 === count($selectedRooms)) {
+            $context->buildViolation('Bitte mindestens ein Zimmer/Bett auswählen')
+                ->addViolation();
+        }
+    }
 }
diff --git a/templates/booking/create_step_1.html.twig b/templates/booking/create_step_1.html.twig
index deedf8e..4d751cd 100644
--- a/templates/booking/create_step_1.html.twig
+++ b/templates/booking/create_step_1.html.twig
@@ -9,6 +9,7 @@
                 Unterkunft
             </h2>
             {{ form_start(form) }}
+            {{ form_errors(form) }}
             {% if groupedRooms.by_room is not empty %}
                 <h3>
                     Zimmer