diff --git a/machines/migrations/0093_auto_20180807_1115.py b/machines/migrations/0093_auto_20180807_1115.py
new file mode 100644
index 00000000..866cb87d
--- /dev/null
+++ b/machines/migrations/0093_auto_20180807_1115.py
@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.7 on 2018-08-07 09:15
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('machines', '0092_auto_20180807_0926'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='mx',
+            name='name',
+            field=models.ForeignKey(on_delete=django.db.models.deletion.PROTECT, to='machines.Domain'),
+        ),
+        migrations.AlterField(
+            model_name='mx',
+            name='priority',
+            field=models.PositiveIntegerField(),
+        ),
+    ]
diff --git a/machines/models.py b/machines/models.py
index b9fd9205..f109b217 100644
--- a/machines/models.py
+++ b/machines/models.py
@@ -740,8 +740,8 @@ class Mx(RevMixin, AclMixin, models.Model):
     PRETTY_NAME = "Enregistrements MX"
 
     zone = models.ForeignKey('Extension', on_delete=models.PROTECT)
-    priority = models.PositiveIntegerField(unique=True)
-    name = models.OneToOneField('Domain', on_delete=models.PROTECT)
+    priority = models.PositiveIntegerField()
+    name = models.ForeignKey('Domain', on_delete=models.PROTECT)
 
     class Meta:
         permissions = (