diff --git a/dpdapi/migrations/0001_initial.py b/dpdapi/migrations/0001_initial.py
index 83d93ed..6cce1d7 100644
--- a/dpdapi/migrations/0001_initial.py
+++ b/dpdapi/migrations/0001_initial.py
@@ -46,7 +46,7 @@ class Migration(migrations.Migration):
                 ('updated', models.DateTimeField(auto_now=True)),
                 ('email', models.EmailField(unique=True, max_length=254)),
                 ('password', models.CharField(max_length=109)),
-                ('domain', models.ForeignKey(to='dpdapi.Domain')),
+                ('domain', models.ForeignKey(to='dpdapi.Domain', on_delete=models.CASCADE)),
             ],
             options={
                 'abstract': False,
@@ -56,7 +56,7 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='alias',
             name='domain',
-            field=models.ForeignKey(to='dpdapi.Domain'),
+            field=models.ForeignKey(to='dpdapi.Domain', on_delete=models.CASCADE),
             preserve_default=True,
         ),
     ]
diff --git a/dpdapi/models.py b/dpdapi/models.py
index 2447983..2a027f5 100644
--- a/dpdapi/models.py
+++ b/dpdapi/models.py
@@ -12,7 +12,7 @@ class BaseModel(models.Model):
 class Alias(BaseModel):
     source = models.EmailField(max_length=254)
     destination = models.EmailField(max_length=254)
-    domain = models.ForeignKey('dpdapi.Domain')
+    domain = models.ForeignKey('dpdapi.Domain', models.CASCADE)
     active = models.BooleanField(default=True)
 
     def __str__(self):
@@ -44,7 +44,7 @@ class Domain(BaseModel):
 class User(BaseModel):
     email = models.EmailField(max_length=254, unique=True)
     password = models.CharField(max_length=109)
-    domain = models.ForeignKey('dpdapi.Domain')
+    domain = models.ForeignKey('dpdapi.Domain', models.CASCADE)
 
     def __str__(self):
         return self.email
diff --git a/requirements.txt b/requirements.txt
index c0b1fea..76e23e3 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-Django==1.11.11
+Django==2.0.3
 django-extensions==2.0.6
 django-filter==1.1.0
 djangorestframework==3.7.7