diff --git a/events/migrations/0001_initial.py b/events/migrations/0001_initial.py
index 7036031..a9dac90 100644
--- a/events/migrations/0001_initial.py
+++ b/events/migrations/0001_initial.py
@@ -1,4 +1,4 @@
-# Generated by Django 3.0.8 on 2020-07-22 02:25
+# Generated by Django 3.0.8 on 2020-07-22 13:42
 
 from django.conf import settings
 from django.db import migrations, models
@@ -27,9 +27,13 @@ class Migration(migrations.Migration):
             name='EventRegistration',
             fields=[
                 ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-                ('state', models.CharField(choices=[('I', 'Interested'), ('A', 'Admitted'), ('D', 'Denied')], max_length=1)),
+                ('state', models.CharField(choices=[('I', 'Interested'), ('A', 'Admitted')], max_length=1)),
                 ('event', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='events.Event')),
                 ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
             ],
         ),
+        migrations.AddConstraint(
+            model_name='eventregistration',
+            constraint=models.UniqueConstraint(fields=('event', 'user'), name='user can only register once per event'),
+        ),
     ]