diff --git a/alplora/urls.py b/alplora/urls.py
index 058f5499..8696925d 100644
--- a/alplora/urls.py
+++ b/alplora/urls.py
@@ -3,6 +3,8 @@ from django.conf.urls import url
 from .views import IndexView, LoginView, ContactView
 
 
+app_name = 'alplora'
+
 urlpatterns = [
     url(r'^$', IndexView.as_view(), name='index'),
     url(r'login/', LoginView.as_view(), name='login'),
diff --git a/datacenterlight/cms_models.py b/datacenterlight/cms_models.py
index d1c5c259..f45a7e61 100644
--- a/datacenterlight/cms_models.py
+++ b/datacenterlight/cms_models.py
@@ -33,7 +33,7 @@ class CMSIntegration(models.Model):
         'datacenterlight_calculator',
         related_name='dcl-calculator-placeholder+'
     )
-    domain = models.ForeignKey(Site, null=True, blank=True)
+    domain = models.ForeignKey(Site, null=True, blank=True, on_delete=models.CASCADE)
 
     class Meta:
         unique_together = ('name', 'domain')
@@ -43,7 +43,7 @@ class CMSIntegration(models.Model):
 
 
 class CMSFaviconExtension(PageExtension):
-    favicon = FilerFileField(related_name="cms_favicon_image")
+    favicon = FilerFileField(related_name="cms_favicon_image", on_delete=models.CASCADE)
 
 
 extension_pool.register(CMSFaviconExtension)
@@ -340,6 +340,7 @@ class DCLCalculatorPluginModel(CMSPlugin):
         related_name="dcl_custom_pricing_vm_pricing",
         help_text='Choose a pricing that will be associated with this '
                   'Calculator'
+    , on_delete=models.CASCADE
     )
     vm_type = models.CharField(
         max_length=50, choices=VMTemplate.VM_TYPE_CHOICES,
diff --git a/datacenterlight/tasks.py b/datacenterlight/tasks.py
index 899b506f..9650af92 100644
--- a/datacenterlight/tasks.py
+++ b/datacenterlight/tasks.py
@@ -5,7 +5,7 @@ from celery.exceptions import MaxRetriesExceededError
 from celery.utils.log import get_task_logger
 from django.conf import settings
 from django.core.mail import EmailMessage
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.utils import translation
 from django.utils.translation import ugettext_lazy as _
 
diff --git a/datacenterlight/templatetags/custom_tags.py b/datacenterlight/templatetags/custom_tags.py
index fc39eec7..7f374039 100644
--- a/datacenterlight/templatetags/custom_tags.py
+++ b/datacenterlight/templatetags/custom_tags.py
@@ -2,7 +2,7 @@ import datetime
 import logging
 
 from django import template
-from django.core.urlresolvers import resolve, reverse
+from django.urls import resolve, reverse
 from django.utils.safestring import mark_safe
 from django.utils.translation import activate, get_language, ugettext_lazy as _
 
diff --git a/datacenterlight/urls.py b/datacenterlight/urls.py
index 13296de7..6aa56d83 100644
--- a/datacenterlight/urls.py
+++ b/datacenterlight/urls.py
@@ -7,6 +7,8 @@ from .views import (
     WhyDataCenterLightView, ContactUsView
 )
 
+app_name = 'datacenterlight'
+
 urlpatterns = [
     url(r'^$', IndexView.as_view(), name='index'),
     url(r'^t/$', IndexView.as_view(), name='index_t'),
diff --git a/datacenterlight/views.py b/datacenterlight/views.py
index c708ff6a..7a5a3cd9 100644
--- a/datacenterlight/views.py
+++ b/datacenterlight/views.py
@@ -7,7 +7,7 @@ from django.conf import settings
 from django.contrib import messages
 from django.contrib.auth import login, authenticate
 from django.core.exceptions import ValidationError
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.http import (
     HttpResponseRedirect, JsonResponse, Http404, HttpResponse
 )
diff --git a/digitalglarus/admin.py b/digitalglarus/admin.py
index c887e8d2..cd419d09 100644
--- a/digitalglarus/admin.py
+++ b/digitalglarus/admin.py
@@ -2,7 +2,7 @@ from django.contrib import admin
 from .models import DGGallery, DGPicture, Booking, BookingPrice,\
     MembershipOrder, Membership, MembershipType, BookingOrder, BookingCancellation
 
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from utils.models import ContactMessage
 from django.utils.html import format_html
 
diff --git a/digitalglarus/mixins.py b/digitalglarus/mixins.py
index 18a02239..55372701 100644
--- a/digitalglarus/mixins.py
+++ b/digitalglarus/mixins.py
@@ -1,4 +1,4 @@
-from django.core.urlresolvers import reverse_lazy
+from django.urls import reverse_lazy
 from django.contrib.auth.mixins import LoginRequiredMixin
 from django.views.generic import UpdateView
 from django.db import models
@@ -33,9 +33,9 @@ class IsNotMemberMixin(object):
 
 
 class Ordereable(models.Model):
-    customer = models.ForeignKey(StripeCustomer)
+    customer = models.ForeignKey(StripeCustomer, on_delete=models.CASCADE)
     amount = models.FloatField()
-    billing_address = models.ForeignKey(BillingAddress)
+    billing_address = models.ForeignKey(BillingAddress, on_delete=models.CASCADE)
     created_at = models.DateTimeField(auto_now_add=True)
     approved = models.BooleanField(default=False)
     last4 = models.CharField(max_length=4, blank=True)
diff --git a/digitalglarus/models.py b/digitalglarus/models.py
index fc4289aa..951f545d 100644
--- a/digitalglarus/models.py
+++ b/digitalglarus/models.py
@@ -7,7 +7,7 @@ from django.db import models
 from django.db.models import Q
 from cms.models import CMSPlugin
 from filer.fields.image import FilerImageField
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.utils.functional import cached_property
 from .mixins import Ordereable
 
@@ -72,7 +72,7 @@ class MembershipType(models.Model):
 
 
 class Membership(models.Model):
-    type = models.ForeignKey(MembershipType)
+    type = models.ForeignKey(MembershipType, on_delete=models.CASCADE)
     active = models.BooleanField(default=True)
     start_date = models.DateField()
     end_date = models.DateField()
@@ -141,7 +141,7 @@ class Membership(models.Model):
 
 
 class MembershipOrder(Ordereable, models.Model):
-    membership = models.ForeignKey(Membership)
+    membership = models.ForeignKey(Membership, on_delete=models.CASCADE)
     start_date = models.DateField()
     end_date = models.DateField()
     stripe_subscription_id = models.CharField(max_length=100, null=True)
@@ -268,7 +268,7 @@ class BookingOrder(Ordereable, models.Model):
         (CANCELLED, 'Cancelled')
     )
 
-    booking = models.OneToOneField(Booking)
+    booking = models.OneToOneField(Booking, on_delete=models.CASCADE)
     original_price = models.FloatField()
     special_month_price = models.FloatField()
     status = models.PositiveIntegerField(choices=STATUS_CHOICES, default=1)
@@ -297,7 +297,7 @@ class BookingOrder(Ordereable, models.Model):
 
 class BookingCancellation(models.Model):
 
-    order = models.ForeignKey(BookingOrder)
+    order = models.ForeignKey(BookingOrder, on_delete=models.CASCADE)
     created_at = models.DateTimeField(auto_now=True)
     required_refund = models.BooleanField(default=True)
     refund = models.BooleanField(default=False)
@@ -323,7 +323,7 @@ class Supporter(models.Model):
 
 
 class DGGallery(models.Model):
-    parent = models.ForeignKey('self', blank=True, null=True)
+    parent = models.ForeignKey('self', blank=True, null=True, on_delete=models.CASCADE)
     name = models.CharField(max_length=30)
 
     def __str__(self):
@@ -337,8 +337,8 @@ class DGGallery(models.Model):
 
 
 class DGPicture(models.Model):
-    gallery = models.ForeignKey(DGGallery)
-    image = FilerImageField(related_name='dg_gallery')
+    gallery = models.ForeignKey(DGGallery, on_delete=models.CASCADE)
+    image = FilerImageField(related_name='dg_gallery', on_delete=models.CASCADE)
     description = models.CharField(max_length=60)
 
     def __str__(self):
@@ -346,7 +346,7 @@ class DGPicture(models.Model):
 
 
 class DGGalleryPlugin(CMSPlugin):
-    dgGallery = models.ForeignKey(DGGallery)
+    dgGallery = models.ForeignKey(DGGallery, on_delete=models.CASCADE)
 
 
 class DGSupportersPlugin(CMSPlugin):
diff --git a/digitalglarus/test_views.py b/digitalglarus/test_views.py
index aff11081..db1d03b2 100644
--- a/digitalglarus/test_views.py
+++ b/digitalglarus/test_views.py
@@ -3,8 +3,8 @@ from unittest import mock, skipIf
 
 from django.test import TestCase
 from django.conf import settings
-from django.core.urlresolvers import reverse
-from django.core.urlresolvers import resolve
+from django.urls import reverse
+from django.urls import resolve
 from cms.test_utils.testcases import CMSTestCase
 from django.contrib.auth.tokens import default_token_generator
 from django.utils.http import urlsafe_base64_encode
diff --git a/digitalglarus/urls.py b/digitalglarus/urls.py
index 64a63303..f3bba898 100644
--- a/digitalglarus/urls.py
+++ b/digitalglarus/urls.py
@@ -13,6 +13,8 @@ from .views import ContactView, IndexView, HistoryView, LoginView, SignupView,\
 
 # from membership.views import LoginRegistrationView
 
+app_name = 'digitalglarus'
+
 urlpatterns = [
     url(_(r'booking/payment/edit/?$'),
         EditCreditCardView.as_view(), name='edit_credit_card'),
@@ -22,8 +24,8 @@ urlpatterns = [
     url(_(r'contact/?$'), ContactView.as_view(), name='contact'),
     url(_(r'login/?$'), LoginView.as_view(), name='login'),
     url(_(r'signup/?$'), SignupView.as_view(), name='signup'),
-    url(r'^logout/?$', auth_views.logout,
-        {'next_page': '/digitalglarus/login?logged_out=true'}, name='logout'),
+    url(r'^logout/?$', auth_views.LogoutView.as_view(
+        next_page='/digitalglarus/login?logged_out=true'), name='logout'),
     url(r'reset-password/?$', PasswordResetView.as_view(), name='reset_password'),
     url(r'reset-password-confirm/(?P<uidb64>[0-9A-Za-z]+)-(?P<token>.+)/$',
         PasswordResetConfirmView.as_view(), name='reset_password_confirm'),
diff --git a/digitalglarus/views.py b/digitalglarus/views.py
index bf3ed2c6..3603dd55 100644
--- a/digitalglarus/views.py
+++ b/digitalglarus/views.py
@@ -3,7 +3,7 @@ import logging
 from django.conf import settings
 from django.shortcuts import render
 from django.http import HttpResponseRedirect, Http404
-from django.core.urlresolvers import reverse_lazy, reverse
+from django.urls import reverse_lazy, reverse
 from django.utils.translation import ugettext_lazy as _
 from django.views.generic import TemplateView, UpdateView
 from django.contrib.auth.mixins import LoginRequiredMixin
diff --git a/dynamicweb/urls.py b/dynamicweb/urls.py
index b9a02981..9dd257c5 100644
--- a/dynamicweb/urls.py
+++ b/dynamicweb/urls.py
@@ -15,7 +15,7 @@ from webhook import views as webhook_views
 from membership import urls as membership_urls
 from ungleich_page.views import LandingView
 from django.views.generic import RedirectView
-from django.core.urlresolvers import reverse_lazy
+from django.urls import reverse_lazy
 import debug_toolbar
 
 urlpatterns = [
@@ -30,7 +30,7 @@ urlpatterns = [
         name="django.hosting"),
     url(r'^nosystemd/', include('nosystemd.urls', namespace="nosystemd")),
     url(r'^taggit_autosuggest/', include('taggit_autosuggest.urls')),
-    url(r'^jsi18n/(?P<packages>\S+?)/$', i18n.javascript_catalog),
+    url(r'^jsi18n/(?P<packages>\S+?)/$', i18n.JavaScriptCatalog.as_view()),
     url(r'^product/(?P<product_slug>[\w-]+)/$',
         PaymentOrderView.as_view(),
         name='show_product'),
@@ -51,7 +51,7 @@ def home_view(request, *args, **kwargs):
 
 
 urlpatterns += i18n_patterns(
-    url(r'^admin/', include(admin.site.urls)),
+    url(r'^admin/', admin.site.urls),
     url(r'^datacenterlight/',
         include('datacenterlight.urls', namespace="datacenterlight")),
     url(r'^hosting/', RedirectView.as_view(url=reverse_lazy('hosting:login')),
diff --git a/dynamicweb/urls_multi.py b/dynamicweb/urls_multi.py
index ffe59db5..44fc57c5 100644
--- a/dynamicweb/urls_multi.py
+++ b/dynamicweb/urls_multi.py
@@ -6,7 +6,7 @@ from django.views import static as static_view
 from django.views.generic import RedirectView
 
 urlpatterns = i18n_patterns(
-    url(r'^admin/', include(admin.site.urls)),
+    url(r'^admin/', admin.site.urls),
     url(r'^cms/', include('cms.urls')),
     url(r'^$', RedirectView.as_view(url='/cms')),
 )
diff --git a/hosting/mixins.py b/hosting/mixins.py
index 5fb83383..dfb010cf 100644
--- a/hosting/mixins.py
+++ b/hosting/mixins.py
@@ -1,6 +1,6 @@
 from django.shortcuts import redirect
 from django.conf import settings
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from opennebula_api.serializers import VirtualMachineTemplateSerializer
 from opennebula_api.models import OpenNebulaManager
diff --git a/hosting/test_views.py b/hosting/test_views.py
index 324aa4fa..60f87a5b 100644
--- a/hosting/test_views.py
+++ b/hosting/test_views.py
@@ -1,7 +1,7 @@
 from django.conf import settings
 from django.test import TestCase
-from django.core.urlresolvers import reverse
-from django.core.urlresolvers import resolve
+from django.urls import reverse
+from django.urls import resolve
 from django.contrib.auth.tokens import default_token_generator
 from django.utils.http import urlsafe_base64_encode
 from django.utils.encoding import force_bytes
diff --git a/hosting/urls.py b/hosting/urls.py
index e34d27d6..c7437460 100644
--- a/hosting/urls.py
+++ b/hosting/urls.py
@@ -14,6 +14,8 @@ from .views import (
     InvoiceListView, InvoiceDetailView, CheckUserVM
 )
 
+app_name = 'hosting'
+
 urlpatterns = [
     url(r'index/?$', IndexView.as_view(), name='index'),
     url(r'django/?$', DjangoHostingView.as_view(), name='djangohosting'),
@@ -69,8 +71,8 @@ urlpatterns = [
         name='reset_password'),
     url(r'reset-password-confirm/(?P<uidb64>[0-9A-Za-z]+)-(?P<token>.+)/$',
         PasswordResetConfirmView.as_view(), name='reset_password_confirm'),
-    url(r'^logout/?$', auth_views.logout,
-        {'next_page': '/hosting/login?logged_out=true'}, name='logout'),
+    url(r'^logout/?$', auth_views.LogoutView.as_view(
+        next_page='/hosting/login?logged_out=true'), name='logout'),
     url(r'^validate/(?P<validate_slug>.*)/$',
         SignupValidatedView.as_view(), name='validate')
 ]
diff --git a/hosting/views.py b/hosting/views.py
index c2470707..5f982157 100644
--- a/hosting/views.py
+++ b/hosting/views.py
@@ -13,7 +13,7 @@ from django.contrib.auth.tokens import default_token_generator
 from django.core.exceptions import ValidationError
 from django.core.files.base import ContentFile
 from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
-from django.core.urlresolvers import reverse_lazy, reverse
+from django.urls import reverse_lazy, reverse
 from django.db.models import Q
 from django.http import (
     Http404, HttpResponseRedirect, HttpResponse, JsonResponse
diff --git a/membership/migrations/0001_initial.py b/membership/migrations/0001_initial.py
index 1704515c..8202c46c 100644
--- a/membership/migrations/0001_initial.py
+++ b/membership/migrations/0001_initial.py
@@ -36,7 +36,7 @@ class Migration(migrations.Migration):
                 ('expiry_date', models.CharField(validators=[django.core.validators.RegexValidator('\\d{2}\\/\\d{4}', 'Use this pattern(MM/YYYY).')], max_length=50)),
                 ('ccv', models.CharField(validators=[django.core.validators.RegexValidator('\\d{3,4}', 'Wrong CCV number.')], max_length=4)),
                 ('payment_type', models.CharField(max_length=5, default='N')),
-                ('user_id', models.ForeignKey(to=settings.AUTH_USER_MODEL)),
+                ('user_id', models.ForeignKey(to=settings.AUTH_USER_MODEL, on_delete=models.CASCADE)),
             ],
         ),
     ]
diff --git a/membership/models.py b/membership/models.py
index abf30467..600aae4d 100644
--- a/membership/models.py
+++ b/membership/models.py
@@ -8,7 +8,7 @@ from django.contrib.auth.hashers import make_password
 from django.contrib.auth.models import AbstractBaseUser, BaseUserManager, \
     PermissionsMixin
 from django.contrib.sites.models import Site
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.core.validators import RegexValidator
 from django.db import models, IntegrityError
 from django.utils.crypto import get_random_string
@@ -113,7 +113,7 @@ def validate_name(value):
 
 class CustomUser(AbstractBaseUser, PermissionsMixin):
     VALIDATED_CHOICES = ((0, 'Not validated'), (1, 'Validated'))
-    site = models.ForeignKey(Site, default=1)
+    site = models.ForeignKey(Site, default=1, on_delete=models.CASCADE)
     name = models.CharField(max_length=50, validators=[validate_name])
     email = models.EmailField(unique=True)
     username = models.CharField(max_length=60, unique=True, null=True)
@@ -267,7 +267,7 @@ class CustomUser(AbstractBaseUser, PermissionsMixin):
 
 
 class StripeCustomer(models.Model):
-    user = models.OneToOneField(CustomUser)
+    user = models.OneToOneField(CustomUser, on_delete=models.CASCADE)
     stripe_id = models.CharField(unique=True, max_length=100)
 
     def __str__(self):
@@ -359,7 +359,7 @@ class DeletedUser(models.Model):
 
 class Calendar(models.Model):
     datebooked = models.DateField()
-    user = models.ForeignKey(CustomUser)
+    user = models.ForeignKey(CustomUser, on_delete=models.CASCADE)
 
     def __init__(self, *args, **kwargs):
         if kwargs.get('datebooked'):
diff --git a/membership/tests.py b/membership/tests.py
index 4b36fe4c..04a3bfdf 100644
--- a/membership/tests.py
+++ b/membership/tests.py
@@ -1,7 +1,7 @@
 # import re
 
 # from django.test import TestCase
-# from django.core.urlresolvers import reverse
+# from django.urls import reverse
 # from django.core import mail
 
 
diff --git a/nosystemd/admin.py b/nosystemd/admin.py
index b07cea8c..93a912fc 100644
--- a/nosystemd/admin.py
+++ b/nosystemd/admin.py
@@ -1,6 +1,6 @@
 from django.contrib import admin
 from django.utils.html import format_html
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from .models import Donation
 
diff --git a/nosystemd/models.py b/nosystemd/models.py
index 76d8ca40..db7ba9ce 100644
--- a/nosystemd/models.py
+++ b/nosystemd/models.py
@@ -11,7 +11,7 @@ class DonatorStatus(models.Model):
         (ACTIVE, 'Active'),
         (CANCELED, 'Canceled')
     )
-    user = models.OneToOneField(CustomUser)
+    user = models.OneToOneField(CustomUser, on_delete=models.CASCADE)
     status = models.CharField(choices=STATUS_CHOICES, max_length=10, default=ACTIVE)
 
     def __str__(self):
@@ -29,9 +29,9 @@ class DonatorStatus(models.Model):
 class Donation(models.Model):
 
     donation = models.FloatField()
-    donator = models.ForeignKey(StripeCustomer)
+    donator = models.ForeignKey(StripeCustomer, on_delete=models.CASCADE)
     created_at = models.DateTimeField(auto_now_add=True)
-    billing_address = models.ForeignKey(BillingAddress)
+    billing_address = models.ForeignKey(BillingAddress, on_delete=models.CASCADE)
     last4 = models.CharField(max_length=4)
     cc_brand = models.CharField(max_length=10)
     stripe_charge_id = models.CharField(max_length=100, null=True)
diff --git a/nosystemd/urls.py b/nosystemd/urls.py
index 7c3965f8..7a9395ec 100644
--- a/nosystemd/urls.py
+++ b/nosystemd/urls.py
@@ -5,12 +5,14 @@ from .views import LandingView, LoginView, SignupView, PasswordResetView,\
     PasswordResetConfirmView, DonationView, DonationDetailView, ChangeDonatorStatusDetailView,\
     DonatorStatusDetailView, DonationListView
 
+app_name = 'nosystemd'
+
 urlpatterns = [
     url(r'^$', LandingView.as_view(), name='landing'),
     url(r'^login/?$', LoginView.as_view(), name='login'),
     url(r'^signup/?$', SignupView.as_view(), name='signup'),
-    url(r'^logout/?$', auth_views.logout,
-        {'next_page': '/nosystemd/login?logged_out=true'}, name='logout'),
+    url(r'^logout/?$', auth_views.LogoutView.as_view(
+        next_page='/nosystemd/login?logged_out=true'), name='logout'),
     url(r'reset-password/?$', PasswordResetView.as_view(), name='reset_password'),
     url(r'reset-password-confirm/(?P<uidb64>[0-9A-Za-z]+)-(?P<token>.+)/$',
         PasswordResetConfirmView.as_view(), name='reset_password_confirm'),
diff --git a/nosystemd/views.py b/nosystemd/views.py
index cca19e8d..7f6e0fc7 100644
--- a/nosystemd/views.py
+++ b/nosystemd/views.py
@@ -2,7 +2,7 @@ from django.views.generic import TemplateView, FormView, DetailView, UpdateView,
     ListView
 from django.http import HttpResponseRedirect
 from django.shortcuts import render
-from django.core.urlresolvers import reverse_lazy, reverse
+from django.urls import reverse_lazy, reverse
 from django.contrib.auth.mixins import LoginRequiredMixin
 from django.conf import settings
 from django.contrib import messages
diff --git a/opennebula_api/urls.py b/opennebula_api/urls.py
index 87976e2e..4fd002f5 100644
--- a/opennebula_api/urls.py
+++ b/opennebula_api/urls.py
@@ -2,6 +2,8 @@ from django.conf.urls import url, include
 from rest_framework.urlpatterns import format_suffix_patterns
 from .views import VmCreateView, VmDetailsView
 
+app_name = 'opennebula_api'
+
 urlpatterns = {
     url(r'^auth/', include('rest_framework.urls', namespace='rest_framework')),
 
diff --git a/ungleich/migrations/0001_initial.py b/ungleich/migrations/0001_initial.py
index 1672c3cc..96093191 100644
--- a/ungleich/migrations/0001_initial.py
+++ b/ungleich/migrations/0001_initial.py
@@ -16,8 +16,8 @@ class Migration(migrations.Migration):
             fields=[
                 ('id', models.AutoField(serialize=False, primary_key=True, auto_created=True, verbose_name='ID')),
                 ('image_header', models.ImageField(upload_to='image_header')),
-                ('extended_object', models.OneToOneField(editable=False, to='cms.Page')),
-                ('public_extension', models.OneToOneField(editable=False, related_name='draft_extension', null=True, to='ungleich.UngleichPage')),
+                ('extended_object', models.OneToOneField(editable=False, to='cms.Page', on_delete=models.CASCADE)),
+                ('public_extension', models.OneToOneField(editable=False, related_name='draft_extension', null=True, to='ungleich.UngleichPage', on_delete=models.CASCADE)),
             ],
             options={
                 'abstract': False,
diff --git a/ungleich/migrations/0002_ungleichpage_image.py b/ungleich/migrations/0002_ungleichpage_image.py
index 44a6be64..b816171b 100644
--- a/ungleich/migrations/0002_ungleichpage_image.py
+++ b/ungleich/migrations/0002_ungleichpage_image.py
@@ -15,7 +15,7 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='ungleichpage',
             name='image',
-            field=filer.fields.image.FilerImageField(null=True, related_name='ungleinch_page_image', to='filer.Image', blank=True),
+            field=filer.fields.image.FilerImageField(null=True, related_name='ungleinch_page_image', to='filer.Image', blank=True, on_delete=models.CASCADE),
             preserve_default=True,
         ),
     ]
diff --git a/ungleich/models.py b/ungleich/models.py
index 194fdfef..cb5001bd 100644
--- a/ungleich/models.py
+++ b/ungleich/models.py
@@ -1,3 +1,4 @@
+from django.db import models
 from cms.extensions import PageExtension
 from cms.extensions.extension_pool import extension_pool
 from filer.fields.image import FilerImageField
@@ -9,7 +10,7 @@ from filer.fields.image import FilerImageField
 class UngleichPage(PageExtension):
     # image_header = models.ImageField(upload_to='image_header')
     image = FilerImageField(null=True, blank=True,
-                            related_name="ungleinch_page_image")
+                            related_name="ungleinch_page_image", on_delete=models.CASCADE)
 
     class Meta:
         app_label = 'ungleich'
diff --git a/ungleich/test_views.py b/ungleich/test_views.py
index 17130857..d766562d 100644
--- a/ungleich/test_views.py
+++ b/ungleich/test_views.py
@@ -1,7 +1,7 @@
 from utils.tests import BaseTestCase
 from django.conf import settings
-from django.core.urlresolvers import reverse
-from django.core.urlresolvers import resolve
+from django.urls import reverse
+from django.urls import resolve
 from django.utils.translation import get_language
 from django.utils.translation import activate
 from djangocms_blog.settings import get_setting
diff --git a/ungleich/urls.py b/ungleich/urls.py
index e833f03d..0991b97d 100644
--- a/ungleich/urls.py
+++ b/ungleich/urls.py
@@ -2,6 +2,8 @@ from django.conf.urls import url
 from . import views
 from .views import PostDetailViewUngleich
 
+app_name = 'ungleich'
+
 urlpatterns = [
     url(r'^$', views.PostListViewUngleich.as_view(), name="post-list"),
     # url(r'^$',views.PostListView.as_view()),
diff --git a/ungleich_page/test_views.py b/ungleich_page/test_views.py
index d67708bd..0fb238cb 100644
--- a/ungleich_page/test_views.py
+++ b/ungleich_page/test_views.py
@@ -1,6 +1,6 @@
 from django.test import TestCase
-from django.core.urlresolvers import reverse
-from django.core.urlresolvers import resolve
+from django.urls import reverse
+from django.urls import resolve
 
 
 class ContactViewTest(TestCase):
diff --git a/ungleich_page/urls.py b/ungleich_page/urls.py
index 607b7042..9f13f9b2 100644
--- a/ungleich_page/urls.py
+++ b/ungleich_page/urls.py
@@ -2,6 +2,8 @@ from django.conf.urls import url
 from .views import ContactView, LandingView
 from django.utils.translation import ugettext_lazy as _
 
+app_name = 'ungleich_page'
+
 urlpatterns = [
     url(r'^$', LandingView.as_view(), name='landing'),
     # url(r'^ungleich_page/?$', LandingView.as_view(), name='landing'),
diff --git a/ungleich_page/views.py b/ungleich_page/views.py
index 01d1138d..a7864675 100644
--- a/ungleich_page/views.py
+++ b/ungleich_page/views.py
@@ -2,7 +2,7 @@ from django.contrib import messages
 
 from django.views.generic.edit import FormView
 from django.utils.translation import ugettext_lazy as _
-from django.core.urlresolvers import reverse_lazy
+from django.urls import reverse_lazy
 from django.views.generic import View
 from django.shortcuts import render
 
diff --git a/utils/models.py b/utils/models.py
index 9e643707..98882c52 100644
--- a/utils/models.py
+++ b/utils/models.py
@@ -40,7 +40,7 @@ class BillingAddress(BaseBillingAddress):
 
 
 class UserBillingAddress(BaseBillingAddress):
-    user = models.ForeignKey(CustomUser, related_name='billing_addresses')
+    user = models.ForeignKey(CustomUser, related_name='billing_addresses', on_delete=models.CASCADE)
     current = models.BooleanField(default=True)
 
     def __str__(self):
diff --git a/utils/views.py b/utils/views.py
index f30a349a..fc851c18 100644
--- a/utils/views.py
+++ b/utils/views.py
@@ -5,7 +5,7 @@ from django.contrib import messages
 from django.contrib.auth import authenticate, login
 from django.contrib.auth.tokens import default_token_generator
 from django.core.files.base import ContentFile
-from django.core.urlresolvers import reverse_lazy
+from django.urls import reverse_lazy
 from django.http import HttpResponseRedirect
 from django.shortcuts import render
 from django.utils.encoding import force_bytes