diff --git a/competition/models.py b/competition/models.py
index e5cc3ec0..ff4b0054 100644
--- a/competition/models.py
+++ b/competition/models.py
@@ -119,6 +119,20 @@ def __str__(self):
         return self.name
 
 
+class RegistrationLink(models.Model):
+    class Meta:
+        verbose_name = 'link na registráciu'
+        verbose_name_plural = 'linky na registráciu'
+
+    url = models.URLField(verbose_name='url registrácie')
+    start = models.DateTimeField(verbose_name='Začiatok registrácie')
+    end = models.DateTimeField(verbose_name='Koniec registrácie')
+    additional_info = models.TextField(verbose_name='Doplňujúce informácie')
+
+    def can_user_modify(self, user):
+        return self.event.can_user_modify(user)
+
+
 class Event(models.Model):
     """
     Slúži na označenie instancie súťaže (Napríklad: Matboj 2020,
@@ -150,7 +164,13 @@ class Meta:
     start = models.DateTimeField(verbose_name='dátum začiatku súťaže')
     end = models.DateTimeField(verbose_name='dátum konca súťaže')
     additional_name = models.CharField(
-        max_length=50, verbose_name='Prísvlastok súťaže', null=True, blank=True)
+        max_length=50, verbose_name='Prívlastok súťaže', null=True, blank=True)
+
+    registration_link = models.ForeignKey(
+        RegistrationLink,
+        on_delete=models.SET_NULL,
+        null=True,
+    )
 
     objects = ActiveQuerySet.as_manager()
 
@@ -629,22 +649,6 @@ def make_name_on_creation(sender, instance, created, **kwargs):
         instance.generate_name()
 
 
-class RegistrationLink(models.Model):
-    class Meta:
-        verbose_name = 'link na registráciu'
-        verbose_name_plural = 'linky na registráciu'
-
-    event = models.OneToOneField(
-        Event, related_name='registration_link', on_delete=models.CASCADE)
-    url = models.URLField(verbose_name='url registrácie')
-    start = models.DateTimeField(verbose_name='Začiatok registrácie')
-    end = models.DateTimeField(verbose_name='Koniec registrácie')
-    additional_info = models.TextField(verbose_name='Doplňujúce informácie')
-
-    def can_user_modify(self, user):
-        return self.event.can_user_modify(user)
-
-
 class ProblemCorrection(models.Model):
     # TODO: Add images
     class Meta:
diff --git a/competition/serializers.py b/competition/serializers.py
index 655d8f9e..404daf73 100644
--- a/competition/serializers.py
+++ b/competition/serializers.py
@@ -3,7 +3,7 @@
 from rest_framework import serializers
 
 from competition import models
-from competition.models import Problem
+from competition.models import Problem, RegistrationLink, Event
 from personal.serializers import ProfileShortSerializer, SchoolShortSerializer
 
 
@@ -43,13 +43,27 @@ class Meta:
 
 @ts_interface(context='competition')
 class EventSerializer(ModelWithParticipationSerializer):
-    publication_set = PublicationSerializer(many=True)
-    registration_link = RegistrationLinkSerializer(many=False)
+    publication_set = PublicationSerializer(many=True, read_only=True)
+    registration_link = RegistrationLinkSerializer(
+        many=False,
+        required=False,
+        allow_null=True,
+    )
 
     class Meta:
         model = models.Event
         fields = '__all__'
 
+    def create(self, validated_data):
+        registration_link = RegistrationLink.objects.create(
+            **validated_data.pop('registration_link'),
+        )
+
+        return Event.objects.create(
+            registration_link=registration_link,
+            **validated_data,
+        )
+
 
 @ts_interface(context='competition')
 class CompetitionTypeSerializer(serializers.ModelSerializer):