diff --git a/machines/migrations/0080_auto_20180502_2334.py b/machines/migrations/0080_auto_20180502_2334.py
new file mode 100644
index 00000000..7097dde2
--- /dev/null
+++ b/machines/migrations/0080_auto_20180502_2334.py
@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.6 on 2018-05-03 04:34
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('machines', '0079_auto_20180416_0107'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='ns',
+            name='ns',
+            field=models.ForeignKey(on_delete=django.db.models.deletion.PROTECT, to='machines.Domain'),
+        ),
+    ]
diff --git a/machines/models.py b/machines/models.py
index 9ed973f2..9eb6323a 100644
--- a/machines/models.py
+++ b/machines/models.py
@@ -613,7 +613,7 @@ class Ns(RevMixin, AclMixin, models.Model):
     PRETTY_NAME = "Enregistrements NS"
 
     zone = models.ForeignKey('Extension', on_delete=models.PROTECT)
-    ns = models.OneToOneField('Domain', on_delete=models.PROTECT)
+    ns = models.ForeignKey('Domain', on_delete=models.PROTECT)
 
     class Meta:
         permissions = (