diff --git a/ticdesk_events/models.py b/ticdesk_events/models.py
index c5ad24905e3853b4cafee13e9c05780580178c4e..478659fa829607e82a54d15d186ab3a9fc9d118f 100644
--- a/ticdesk_events/models.py
+++ b/ticdesk_events/models.py
@@ -22,6 +22,7 @@ class Voucher(models.Model):
 class RegistrationField(models.Model):
     class Meta:
         app_label = 'ticdesk_events'
+        unique_together = ('project_cn', 'person_uid', 'title')
 
     project_cn = models.CharField(max_length=50)
     person_uid = models.CharField(max_length=20)