diff --git a/categories/base.py b/categories/base.py
index 6d02b87..eb1ccd3 100644
--- a/categories/base.py
+++ b/categories/base.py
@@ -37,10 +37,12 @@ class CategoryBase(MPTTModel):
     """
     parent = TreeForeignKey(
         'self',
+        on_delete=models.CASCADE,
         blank=True,
         null=True,
         related_name='children',
-        verbose_name=_('parent'))
+        verbose_name=_('parent'),
+    )
     name = models.CharField(max_length=100, verbose_name=_('name'))
     slug = models.SlugField(verbose_name=_('slug'))
     active = models.BooleanField(default=True, verbose_name=_('active'))
diff --git a/categories/editor/templatetags/admin_tree_list_tags.py b/categories/editor/templatetags/admin_tree_list_tags.py
index 681df55..6ef6e95 100644
--- a/categories/editor/templatetags/admin_tree_list_tags.py
+++ b/categories/editor/templatetags/admin_tree_list_tags.py
@@ -41,7 +41,7 @@ def items_for_tree_result(cl, result, form):
             result_repr = get_empty_value_display(cl)
         else:
             if f is None:
-                if django.VERSION[1] == 4:
+                if django.VERSION[0] == 1 and django.VERSION[1] == 4:
                     if field_name == 'action_checkbox':
                         row_class = ' class="action-checkbox disclosure"'
                 allow_tags = getattr(attr, 'allow_tags', False)
@@ -60,14 +60,14 @@ def items_for_tree_result(cl, result, form):
             else:
                 if value is None:
                     result_repr = get_empty_value_display(cl)
-                if isinstance(f.rel, models.ManyToOneRel):
+                if hasattr(f, 'rel') and isinstance(f.rel, models.ManyToOneRel):
                     result_repr = escape(getattr(result, f.name))
                 else:
                     result_repr = display_for_field(value, f, '')
                 if isinstance(f, models.DateField) or isinstance(f, models.TimeField):
                     row_class = ' class="nowrap"'
             if first:
-                if django.VERSION[1] < 4:
+                if django.VERSION[0] == 1 and django.VERSION[1] < 4:
                     try:
                         f, attr, checkbox_value = lookup_field('action_checkbox', result, cl.model_admin)
                         if row_class:
@@ -81,7 +81,7 @@ def items_for_tree_result(cl, result, form):
             result_repr = mark_safe('&nbsp;')
         # If list_display_links not defined, add the link tag to the first field
         if (first and not cl.list_display_links) or field_name in cl.list_display_links:
-            if django.VERSION[1] < 4:
+            if django.VERSION[0] == 1 and django.VERSION[1] < 4:
                 table_tag = 'td'  # {True:'th', False:'td'}[first]
             else:
                 table_tag = {True: 'th', False: 'td'}[first]
@@ -160,7 +160,7 @@ def result_tree_list(cl):
         'result_headers': list(result_headers(cl)),
         'results': list(tree_results(cl))
     }
-    if django.VERSION[1] > 2:
+    if django.VERSION[0] == 1 and django.VERSION[1] > 2:
         from django.contrib.admin.templatetags.admin_list import result_hidden_fields
         result['result_hidden_fields'] = list(result_hidden_fields(cl))
     return result
diff --git a/categories/editor/tree_editor.py b/categories/editor/tree_editor.py
index 2169e5d..ff2c135 100644
--- a/categories/editor/tree_editor.py
+++ b/categories/editor/tree_editor.py
@@ -67,13 +67,13 @@ class TreeEditorQuerySet(QuerySet):
 
 class TreeChangeList(ChangeList):
     def _get_default_ordering(self):
-        if django.VERSION[1] < 4:
+        if django.VERSION[0] == 1 and django.VERSION[1] < 4:
             return '', ''  # ('tree_id', 'lft')
         else:
             return []
 
     def get_ordering(self, request=None, queryset=None):
-        if django.VERSION[1] < 4:
+        if django.VERSION[0] == 1 and django.VERSION[1] < 4:
             return '', ''  # ('tree_id', 'lft')
         else:
             return []
@@ -142,7 +142,7 @@ class TreeEditor(admin.ModelAdmin):
                 pass
 
         try:
-            if django.VERSION[1] < 4:
+            if django.VERSION[0] == 1 and django.VERSION[1] < 4:
                 params = (
                     request, self.model, list_display,
                     self.list_display_links, self.list_filter, self.date_hierarchy,
@@ -241,7 +241,7 @@ class TreeEditor(admin.ModelAdmin):
             'actions_on_top': self.actions_on_top,
             'actions_on_bottom': self.actions_on_bottom,
         }
-        if django.VERSION[1] < 4:
+        if django.VERSION[0] == 1 and django.VERSION[1] < 4:
             context['root_path'] = self.admin_site.root_path
         else:
             selection_note_all = ungettext('%(total_count)s selected', 'All %(total_count)s selected', cl.result_count)
diff --git a/categories/genericcollection.py b/categories/genericcollection.py
index ecca82c..ffa01a0 100644
--- a/categories/genericcollection.py
+++ b/categories/genericcollection.py
@@ -1,6 +1,6 @@
 from django.contrib import admin
 from django.contrib.contenttypes.models import ContentType
-from django.core.urlresolvers import reverse, NoReverseMatch
+from django.urls import reverse, NoReverseMatch
 import json
 
 
diff --git a/categories/migrations/0001_initial.py b/categories/migrations/0001_initial.py
index ffd6beb..b58fabc 100644
--- a/categories/migrations/0001_initial.py
+++ b/categories/migrations/0001_initial.py
@@ -33,7 +33,7 @@ class Migration(migrations.Migration):
                 ('rght', models.PositiveIntegerField(editable=False, db_index=True)),
                 ('tree_id', models.PositiveIntegerField(editable=False, db_index=True)),
                 ('level', models.PositiveIntegerField(editable=False, db_index=True)),
-                ('parent', mptt.fields.TreeForeignKey(related_name='children', verbose_name='parent', blank=True, to='categories.Category', null=True)),
+                ('parent', mptt.fields.TreeForeignKey(related_name='children', verbose_name='parent', blank=True, to='categories.Category', on_delete=models.CASCADE, null=True)),
             ],
             options={
                 'ordering': ('tree_id', 'lft'),
@@ -48,8 +48,8 @@ class Migration(migrations.Migration):
                 ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
                 ('object_id', models.PositiveIntegerField(verbose_name='object id')),
                 ('relation_type', models.CharField(help_text="A generic text field to tag a relation, like 'leadphoto'.", max_length='200', null=True, verbose_name='relation type', blank=True)),
-                ('category', models.ForeignKey(verbose_name='category', to='categories.Category')),
-                ('content_type', models.ForeignKey(verbose_name='content type', to='contenttypes.ContentType')),
+                ('category', models.ForeignKey(verbose_name='category', to='categories.Category', on_delete=models.CASCADE)),
+                ('content_type', models.ForeignKey(verbose_name='content type', to='contenttypes.ContentType', on_delete=models.CASCADE)),
             ],
         ),
         migrations.AlterUniqueTogether(
diff --git a/categories/models.py b/categories/models.py
index f8b31e3..15ddecb 100644
--- a/categories/models.py
+++ b/categories/models.py
@@ -1,5 +1,5 @@
 from django.core.files.images import get_image_dimensions
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.db import models
 from django.utils.encoding import force_text
 from django.contrib.contenttypes.models import ContentType
@@ -55,7 +55,7 @@ class Category(CategoryBase):
 
     def get_absolute_url(self):
         """Return a path"""
-        from django.core.urlresolvers import NoReverseMatch
+        from django.urls import NoReverseMatch
 
         if self.alternate_url:
             return self.alternate_url
@@ -123,9 +123,9 @@ class CategoryRelationManager(models.Manager):
 
 class CategoryRelation(models.Model):
     """Related category item"""
-    category = models.ForeignKey(Category, verbose_name=_('category'))
+    category = models.ForeignKey(Category, verbose_name=_('category'), on_delete=models.CASCADE)
     content_type = models.ForeignKey(
-        ContentType, limit_choices_to=CATEGORY_RELATION_LIMITS, verbose_name=_('content type'))
+        ContentType, on_delete=models.CASCADE, limit_choices_to=CATEGORY_RELATION_LIMITS, verbose_name=_('content type'))
     object_id = models.PositiveIntegerField(verbose_name=_('object id'))
     content_object = GenericForeignKey('content_type', 'object_id')
     relation_type = models.CharField(
diff --git a/categories/registration.py b/categories/registration.py
index 04cbb13..9aab911 100644
--- a/categories/registration.py
+++ b/categories/registration.py
@@ -62,6 +62,7 @@ class Registry(object):
         for fld in field_definitions:
             extra_params = {'to': 'categories.Category', 'blank': True}
             if field_type != 'ManyToManyField':
+                extra_params['on_delete'] = 'CASCADE'
                 extra_params['null'] = True
             if isinstance(fld, str):
                 field_name = fld
diff --git a/categories/templatetags/category_tags.py b/categories/templatetags/category_tags.py
index 83bc42d..cdc4593 100644
--- a/categories/templatetags/category_tags.py
+++ b/categories/templatetags/category_tags.py
@@ -86,7 +86,7 @@ class CategoryDrillDownNode(template.Node):
                 context[self.varname] = drilldown_tree_for_node(cat)
             else:
                 context[self.varname] = []
-        except:
+        except Exception:
             context[self.varname] = []
         return ''
 
diff --git a/categories/tests/test_admin.py b/categories/tests/test_admin.py
index fb2e05a..20759c1 100644
--- a/categories/tests/test_admin.py
+++ b/categories/tests/test_admin.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 
 from django.contrib.auth.models import User
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.test import Client, TestCase
 from django.utils.encoding import smart_text
 
diff --git a/categories/tests/test_mgmt_commands.py b/categories/tests/test_mgmt_commands.py
index 4646baf..ebe818e 100644
--- a/categories/tests/test_mgmt_commands.py
+++ b/categories/tests/test_mgmt_commands.py
@@ -8,13 +8,13 @@ from django.test import TestCase
 class TestMgmtCommands(TestCase):
 
     def test_add_category_fields(self):
-        management.call_command('add_category_fields', verbosity=0, interactive=False)
+        management.call_command('add_category_fields', verbosity=0)
 
     def test_add_category_fields_app(self):
-        management.call_command('add_category_fields', 'flatpages', verbosity=0, interactive=False)
+        management.call_command('add_category_fields', 'flatpages', verbosity=0)
 
     def test_drop_category_field(self):
-        management.call_command('drop_category_field', 'flatpages', 'flatpage', 'category', verbosity=0, interactive=False)
+        management.call_command('drop_category_field', 'flatpages', 'flatpage', 'category', verbosity=0)
 
     def test_drop_category_field_error(self):
-        self.assertRaises(CommandError, management.call_command, 'drop_category_field', verbosity=0, interactive=False)
+        self.assertRaises(CommandError, management.call_command, 'drop_category_field', verbosity=0)
diff --git a/example/settings-testing.py b/example/settings-testing.py
index 523fa41..9d2c3f1 100644
--- a/example/settings-testing.py
+++ b/example/settings-testing.py
@@ -2,6 +2,8 @@
 import os
 import sys
 
+from django.db import models
+
 APP = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
 PROJ_ROOT = os.path.abspath(os.path.dirname(__file__))
 sys.path.insert(0, APP)
@@ -64,13 +66,14 @@ STATICFILES_FINDERS = (
 
 SECRET_KEY = 'bwq#m)-zsey-fs)0#4*o=2z(v5g!ei=zytl9t-1hesh4b&-u^d'
 
-MIDDLEWARE_CLASSES = (
-    'django.middleware.common.CommonMiddleware',
+MIDDLEWARE = (
+    'django.middleware.security.SecurityMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
     'django.contrib.messages.middleware.MessageMiddleware',
-    'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
 )
 
 ROOT_URLCONF = 'urls'
@@ -99,7 +102,10 @@ CATEGORIES_SETTINGS = {
     'ALLOW_SLUG_CHANGE': True,
     'RELATION_MODELS': ['simpletext.simpletext', 'flatpages.flatpage'],
     'FK_REGISTRY': {
-        'flatpages.flatpage': 'category',
+        'flatpages.flatpage': (
+            'category',
+            {'on_delete': models.CASCADE}
+        ),
         'simpletext.simpletext': (
             'primary_category',
             {'name': 'secondary_category', 'related_name': 'simpletext_sec_cat'},
diff --git a/example/settings.py b/example/settings.py
index 7940187..6eab74a 100644
--- a/example/settings.py
+++ b/example/settings.py
@@ -2,6 +2,7 @@
 import os
 import sys
 import django
+from django.db import models
 
 APP = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
 PROJ_ROOT = os.path.abspath(os.path.dirname(__file__))
@@ -65,12 +66,14 @@ STATICFILES_FINDERS = (
 
 SECRET_KEY = 'bwq#m)-zsey-fs)0#4*o=2z(v5g!ei=zytl9t-1hesh4b&-u^d'
 
-MIDDLEWARE_CLASSES = (
-    'django.middleware.common.CommonMiddleware',
+MIDDLEWARE = (
+    'django.middleware.security.SecurityMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.common.CommonMiddleware',
     'django.middleware.csrf.CsrfViewMiddleware',
     'django.contrib.auth.middleware.AuthenticationMiddleware',
     'django.contrib.messages.middleware.MessageMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
 )
 
 ROOT_URLCONF = 'urls'
@@ -99,7 +102,10 @@ CATEGORIES_SETTINGS = {
     'ALLOW_SLUG_CHANGE': True,
     'RELATION_MODELS': ['simpletext.simpletext', 'flatpages.flatpage'],
     'FK_REGISTRY': {
-        'flatpages.flatpage': 'category',
+        'flatpages.flatpage': (
+            'category',
+            {'on_delete': models.CASCADE}
+        ),
         'simpletext.simpletext': (
             'primary_category',
             {'name': 'secondary_category', 'related_name': 'simpletext_sec_cat'},
diff --git a/example/simpletext/migrations/0002_auto_20171204_0721.py b/example/simpletext/migrations/0002_auto_20171204_0721.py
new file mode 100644
index 0000000..2205f4c
--- /dev/null
+++ b/example/simpletext/migrations/0002_auto_20171204_0721.py
@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.5 on 2017-12-04 07:21
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+import django.db.models.manager
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('categories', '0002_auto_20170217_1111'),
+        ('simpletext', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterModelManagers(
+            name='simplecategory',
+            managers=[
+                ('tree', django.db.models.manager.Manager()),
+            ],
+        ),
+        migrations.AddField(
+            model_name='simpletext',
+            name='categories',
+            field=models.ManyToManyField(blank=True, related_name='m2mcats', to='categories.Category'),
+        ),
+        migrations.AddField(
+            model_name='simpletext',
+            name='primary_category',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='categories.Category'),
+        ),
+        migrations.AddField(
+            model_name='simpletext',
+            name='secondary_category',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='simpletext_sec_cat', to='categories.Category'),
+        ),
+    ]
diff --git a/example/urls.py b/example/urls.py
index 5c660e4..4c34998 100644
--- a/example/urls.py
+++ b/example/urls.py
@@ -18,7 +18,7 @@ urlpatterns = (
     # (r'^admin/doc/', include('django.contrib.admindocs.urls')),
 
     # Uncomment the next line to enable the admin:
-    url(r'^admin/', include(admin.site.urls)),
+    url(r'^admin/', admin.site.urls),
     url(r'^categories/', include('categories.urls')),
     # r'^cats/', include('categories.urls')),
 
diff --git a/requirements.txt b/requirements.txt
index fab2322..731db0d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,2 @@
-django-mptt>=0.8.6,<0.9
+django-mptt>=0.9.0,<0.10
 unicode-slugify==0.1.3
diff --git a/tox.ini b/tox.ini
index 3eae2ec..06fa0ee 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,23 +2,22 @@
 envlist =
     begin
     py27-lint
-    py27-django{18,19,110}
-    py36-django{18,19,110,111}
+    py27-django{110,111}
+    py36-django{110,111,2}
     coverage-report
 
 [testenv]
 deps=
+    django2: Django<2.1
     django111: Django<2.0
     django110: Django<1.11
-    django19: Django<1.10
-    django18: Django<1.9
     coverage
     pillow
     ipdb
     -r{toxinidir}/requirements.txt
 
 commands=
-  coverage run --source=categories --omit='.tox/*,example/*,*/tests/*' {toxinidir}/example/manage.py test --settings='settings-testing' categories
+  coverage run --source=categories --omit='.tox/*,example/*,*/tests/*' {toxinidir}/example/manage.py test --settings='settings-testing' categories{posargs}
 
 [testenv:begin]
 commands = coverage erase