diff --git a/.gitignore b/.gitignore
index e1c8ad4..02bf72b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,4 @@ MANIFEST
 dist/
 .venv
 example/media/
+.tox/
diff --git a/.travis.yml b/.travis.yml
index 7eadf8f..8310e44 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,16 +1,23 @@
 language: python
-python:
-  - "2.7"
-env:
-  - DJANGO_VERSION=1.6.11
-  - DJANGO_VERSION=1.7.7
-  - DJANGO_VERSION=1.8
-install:
-  - pip install Django==$DJANGO_VERSION
-  - pip install -e .
-  - pip install South
-script:
-  - ./example/manage.py test categories --settings='settings-testing' 
+
 branches:
   only:
-    - master
\ No newline at end of file
+    - master
+
+env:
+  - TOXENV=py27-django18
+  - TOXENV=py27-django19
+  - TOXENV=py34-django18
+  - TOXENV=py34-django19
+  - TOXENV=py35-django18
+  - TOXENV=py35-django19
+
+install:
+  - pip install tox
+
+script:
+  - tox -e $TOXENV
+
+after_success:
+  - pip install codecov
+  - codecov -e TOXENV
diff --git a/categories/__init__.py b/categories/__init__.py
index 035da6a..df598df 100644
--- a/categories/__init__.py
+++ b/categories/__init__.py
@@ -29,4 +29,4 @@ def register():
 try:
     register()
 except Exception as e:
-    print e
+    print(e)
diff --git a/categories/admin.py b/categories/admin.py
index c61f26f..26b8949 100644
--- a/categories/admin.py
+++ b/categories/admin.py
@@ -11,7 +11,7 @@ from .settings import MODEL_REGISTRY
 
 class NullTreeNodeChoiceField(forms.ModelChoiceField):
     """A ModelChoiceField for tree nodes."""
-    def __init__(self, level_indicator=u'---', *args, **kwargs):
+    def __init__(self, level_indicator='---', *args, **kwargs):
         self.level_indicator = level_indicator
         super(NullTreeNodeChoiceField, self).__init__(*args, **kwargs)
 
@@ -20,7 +20,7 @@ class NullTreeNodeChoiceField(forms.ModelChoiceField):
         Creates labels which represent the tree level of each node when
         generating option labels.
         """
-        return u'%s %s' % (self.level_indicator * getattr(
+        return '%s %s' % (self.level_indicator * getattr(
                                         obj, obj._mptt_meta.level_attr), obj)
 if RELATION_MODELS:
     from .models import CategoryRelation
@@ -68,8 +68,8 @@ class CategoryAdmin(CategoryBaseAdmin):
 if REGISTER_ADMIN:
     admin.site.register(Category, CategoryAdmin)
 
-for model, modeladmin in admin.site._registry.items():
-    if model in MODEL_REGISTRY.values() and modeladmin.fieldsets:
+for model, modeladmin in list(admin.site._registry.items()):
+    if model in list(MODEL_REGISTRY.values()) and modeladmin.fieldsets:
         fieldsets = getattr(modeladmin, 'fieldsets', ())
         fields = [cat.split('.')[2] for cat in MODEL_REGISTRY if MODEL_REGISTRY[cat] == model]
         # check each field to see if already defined
diff --git a/categories/apps.py b/categories/apps.py
index daab55b..02e70e0 100644
--- a/categories/apps.py
+++ b/categories/apps.py
@@ -26,12 +26,12 @@ def handle_class_prepared(sender, **kwargs):
     sender_app = sender._meta.app_label
     sender_name = sender._meta.model_name
 
-    for key, val in FK_REGISTRY.items():
+    for key, val in list(FK_REGISTRY.items()):
         app_name, model_name = key.split('.')
         if app_name == sender_app and sender_name == model_name:
             registry.register_model(app_name, sender, 'ForeignKey', val)
 
-    for key, val in M2M_REGISTRY.items():
+    for key, val in list(M2M_REGISTRY.items()):
         app_name, model_name = key.split('.')
         if app_name == sender_app and sender_name == model_name:
             registry.register_model(app_name, sender, 'ManyToManyField', val)
diff --git a/categories/base.py b/categories/base.py
index 0c64b08..ff16f8e 100644
--- a/categories/base.py
+++ b/categories/base.py
@@ -6,7 +6,7 @@ with customizable metadata and its own name space.
 from django.contrib import admin
 from django.db import models
 from django import forms
-from django.utils.encoding import force_unicode
+from django.utils.encoding import force_text, python_2_unicode_compatible
 from django.utils.translation import ugettext_lazy as _
 
 from mptt.models import MPTTModel
@@ -29,6 +29,7 @@ class CategoryManager(models.Manager):
         return self.get_queryset().filter(active=True)
 
 
+@python_2_unicode_compatible
 class CategoryBase(MPTTModel):
     """
     This base model includes the absolute bare bones fields and methods. One
@@ -63,9 +64,9 @@ class CategoryBase(MPTTModel):
                     item.active = self.active
                     item.save()
 
-    def __unicode__(self):
+    def __str__(self):
         ancestors = self.get_ancestors()
-        return ' > '.join([force_unicode(i.name) for i in ancestors] + [self.name, ])
+        return ' > '.join([force_text(i.name) for i in ancestors] + [self.name, ])
 
     class Meta:
         abstract = True
diff --git a/categories/editor/templates/admin/editor/grappelli_tree_editor.html b/categories/editor/templates/admin/editor/grappelli_tree_editor.html
index 9bc8ecb..99e64ec 100644
--- a/categories/editor/templates/admin/editor/grappelli_tree_editor.html
+++ b/categories/editor/templates/admin/editor/grappelli_tree_editor.html
@@ -1,5 +1,5 @@
 {% extends "admin/change_list.html" %}
-{% load admin_list i18n admin_tree_list %}
+{% load admin_list i18n admin_tree_list_tags %}
 {% block extrahead %}
     {{ block.super }}
     <script type="text/javascript">
diff --git a/categories/editor/templatetags/admin_tree_list_tags.py b/categories/editor/templatetags/admin_tree_list_tags.py
index a019b2e..efd29f3 100644
--- a/categories/editor/templatetags/admin_tree_list_tags.py
+++ b/categories/editor/templatetags/admin_tree_list_tags.py
@@ -3,12 +3,11 @@ from django.db import models
 from django.template import Library
 from django.contrib.admin.templatetags.admin_list import result_headers, _boolean_icon
 try:
-    from django.contrib.admin.util import lookup_field, display_for_field, label_for_field
+    from django.contrib.admin.utils import lookup_field, display_for_field, label_for_field
 except ImportError:
     from categories.editor.utils import lookup_field, display_for_field, label_for_field
-from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE
 from django.core.exceptions import ObjectDoesNotExist
-from django.utils.encoding import smart_unicode, force_unicode
+from django.utils.encoding import smart_text, force_text
 from django.utils.html import escape, conditional_escape
 from django.utils.safestring import mark_safe
 
@@ -21,6 +20,15 @@ if settings.IS_GRAPPELLI_INSTALLED:
     TREE_LIST_RESULTS_TEMPLATE = 'admin/editor/grappelli_tree_list_results.html'
 
 
+def get_empty_value_display(cl):
+    if hasattr(cl.model_admin, 'get_empty_value_display'):
+        return cl.model_admin.get_empty_value_display()
+    else:
+        # Django < 1.9
+        from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE
+        return EMPTY_CHANGELIST_VALUE
+
+
 def items_for_tree_result(cl, result, form):
     """
     Generates the actual list of data.
@@ -32,7 +40,7 @@ def items_for_tree_result(cl, result, form):
         try:
             f, attr, value = lookup_field(field_name, result, cl.model_admin)
         except (AttributeError, ObjectDoesNotExist):
-            result_repr = EMPTY_CHANGELIST_VALUE
+            result_repr = get_empty_value_display(cl)
         else:
             if f is None:
                 if django.VERSION[1] == 4:
@@ -44,7 +52,7 @@ def items_for_tree_result(cl, result, form):
                     allow_tags = True
                     result_repr = _boolean_icon(value)
                 else:
-                    result_repr = smart_unicode(value)
+                    result_repr = smart_text(value)
                 # Strip HTML tags in the resulting text, except if the
                 # function has an "allow_tags" attribute set to True.
                 if not allow_tags:
@@ -53,7 +61,7 @@ def items_for_tree_result(cl, result, form):
                     result_repr = mark_safe(result_repr)
             else:
                 if value is None:
-                    result_repr = EMPTY_CHANGELIST_VALUE
+                    result_repr = get_empty_value_display(cl)
                 if isinstance(f.rel, models.ManyToOneRel):
                     result_repr = escape(getattr(result, f.name))
                 else:
@@ -71,7 +79,7 @@ def items_for_tree_result(cl, result, form):
                     except (AttributeError, ObjectDoesNotExist):
                         pass
 
-        if force_unicode(result_repr) == '':
+        if force_text(result_repr) == '':
             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:
@@ -88,13 +96,13 @@ def items_for_tree_result(cl, result, form):
             else:
                 attr = pk
             value = result.serializable_value(attr)
-            result_id = repr(force_unicode(value))[1:]
+            result_id = repr(force_text(value))[1:]
             first = False
             if django.VERSION[1] < 4:
-                yield mark_safe(u'<%s%s>%s<a href="%s"%s>%s</a></%s>' % \
+                yield mark_safe('<%s%s>%s<a href="%s"%s>%s</a></%s>' % \
                     (table_tag, row_class, checkbox_value, url, (cl.is_popup and ' onclick="opener.dismissRelatedLookupPopup(window, %s); return false;"' % result_id or ''), conditional_escape(result_repr), table_tag))
             else:
-                yield mark_safe(u'<%s%s><a href="%s"%s>%s</a></%s>' % \
+                yield mark_safe('<%s%s><a href="%s"%s>%s</a></%s>' % \
                     (table_tag, row_class, url, (cl.is_popup and ' onclick="opener.dismissRelatedLookupPopup(window, %s); return false;"' % result_id or ''), conditional_escape(result_repr), table_tag))
 
         else:
@@ -103,12 +111,12 @@ def items_for_tree_result(cl, result, form):
             # can provide fields on a per request basis
             if form and field_name in form.fields:
                 bf = form[field_name]
-                result_repr = mark_safe(force_unicode(bf.errors) + force_unicode(bf))
+                result_repr = mark_safe(force_text(bf.errors) + force_text(bf))
             else:
                 result_repr = conditional_escape(result_repr)
-            yield mark_safe(u'<td%s>%s</td>' % (row_class, result_repr))
+            yield mark_safe('<td%s>%s</td>' % (row_class, result_repr))
     if form and not form[cl.model._meta.pk.name].is_hidden:
-        yield mark_safe(u'<td>%s</td>' % force_unicode(form[cl.model._meta.pk.name]))
+        yield mark_safe('<td>%s</td>' % force_text(form[cl.model._meta.pk.name]))
 
 
 class TreeList(list):
diff --git a/categories/editor/tree_editor.py b/categories/editor/tree_editor.py
index 7df5732..821f6a6 100644
--- a/categories/editor/tree_editor.py
+++ b/categories/editor/tree_editor.py
@@ -9,7 +9,7 @@ from django.shortcuts import render_to_response
 
 import django
 
-import settings
+from . import settings
 
 
 class TreeEditorQuerySet(QuerySet):
@@ -125,7 +125,7 @@ class TreeEditor(admin.ModelAdmin):
         "The 'change list' admin view for this model."
         from django.contrib.admin.views.main import ERROR_FLAG
         from django.core.exceptions import PermissionDenied
-        from django.utils.encoding import force_unicode
+        from django.utils.encoding import force_text
         from django.utils.translation import ungettext
         opts = self.model._meta
         app_label = opts.app_label
@@ -162,7 +162,7 @@ class TreeEditor(admin.ModelAdmin):
             # parameter via the query string. If wacky parameters were given and
             # the 'invalid=1' parameter was already in the query string, something
             # is screwed up with the database, so display an error page.
-            if ERROR_FLAG in request.GET.keys():
+            if ERROR_FLAG in list(request.GET.keys()):
                 return render_to_response(
                     'admin/invalid_setup.html', {'title': _('Database error')})
             return HttpResponseRedirect(request.path + '?' + ERROR_FLAG + '=1')
@@ -199,15 +199,15 @@ class TreeEditor(admin.ModelAdmin):
 
                 if changecount:
                     if changecount == 1:
-                        name = force_unicode(opts.verbose_name)
+                        name = force_text(opts.verbose_name)
                     else:
-                        name = force_unicode(opts.verbose_name_plural)
+                        name = force_text(opts.verbose_name_plural)
                     msg = ungettext(
                         "%(count)s %(name)s was changed successfully.",
                         "%(count)s %(name)s were changed successfully.",
                         changecount) % {'count': changecount,
                                         'name': name,
-                                        'obj': force_unicode(obj)}
+                                        'obj': force_text(obj)}
                     self.message_user(request, msg)
 
                 return HttpResponseRedirect(request.get_full_path())
@@ -248,7 +248,7 @@ class TreeEditor(admin.ModelAdmin):
                 'All %(total_count)s selected', cl.result_count)
 
             context.update({
-                'module_name': force_unicode(opts.verbose_name_plural),
+                'module_name': force_text(opts.verbose_name_plural),
                 'selection_note': _('0 of %(cnt)s selected') % {'cnt': len(cl.result_list)},
                 'selection_note_all': selection_note_all % {'total_count': cl.result_count},
             })
diff --git a/categories/editor/utils.py b/categories/editor/utils.py
index b8d7e78..6664c65 100644
--- a/categories/editor/utils.py
+++ b/categories/editor/utils.py
@@ -1,7 +1,7 @@
 """
 Provides compatibility with Django 1.1
 
-Copied from django.contrib.admin.util
+Copied from django.contrib.admin.utils
 """
 from django.forms.forms import pretty_name
 from django.db import models
@@ -11,6 +11,7 @@ from django.utils.translation import get_date_formats
 from django.utils.text import capfirst
 from django.utils import dateformat
 from django.utils.html import escape
+import collections
 
 
 def lookup_field(name, obj, model_admin=None):
@@ -20,7 +21,7 @@ def lookup_field(name, obj, model_admin=None):
     except models.FieldDoesNotExist:
         # For non-field values, the value is either a method, property or
         # returned via a callable.
-        if callable(name):
+        if isinstance(name, collections.Callable):
             attr = name
             value = attr(obj)
         elif (model_admin is not None and hasattr(model_admin, name) and
@@ -29,7 +30,7 @@ def lookup_field(name, obj, model_admin=None):
             value = attr(obj)
         else:
             attr = getattr(obj, name)
-            if callable(attr):
+            if isinstance(attr, collections.Callable):
                 value = attr()
             else:
                 value = attr
@@ -57,12 +58,12 @@ def label_for_field(name, model, model_admin=None, return_attr=False):
     except models.FieldDoesNotExist:
         if name == "__unicode__":
             label = force_unicode(model._meta.verbose_name)
-            attr = unicode
+            attr = str
         elif name == "__str__":
             label = smart_str(model._meta.verbose_name)
             attr = str
         else:
-            if callable(name):
+            if isinstance(name, collections.Callable):
                 attr = name
             elif model_admin is not None and hasattr(model_admin, name):
                 attr = getattr(model_admin, name)
@@ -76,7 +77,7 @@ def label_for_field(name, model, model_admin=None, return_attr=False):
 
             if hasattr(attr, "short_description"):
                 label = attr.short_description
-            elif callable(attr):
+            elif isinstance(attr, collections.Callable):
                 if attr.__name__ == "<lambda>":
                     label = "--"
                 else:
diff --git a/categories/management/commands/drop_category_field.py b/categories/management/commands/drop_category_field.py
index 3163e01..ed9e710 100644
--- a/categories/management/commands/drop_category_field.py
+++ b/categories/management/commands/drop_category_field.py
@@ -21,6 +21,6 @@ class Command(BaseCommand):
 
         from categories.migration import drop_field
         if len(args) != 3:
-            print "You must specify an Application name, a Model name and a Field name"
+            print("You must specify an Application name, a Model name and a Field name")
 
         drop_field(*args)
diff --git a/categories/management/commands/import_categories.py b/categories/management/commands/import_categories.py
index f0f164e..fe75b23 100644
--- a/categories/management/commands/import_categories.py
+++ b/categories/management/commands/import_categories.py
@@ -81,9 +81,9 @@ class Command(BaseCommand):
 
         for file_path in file_paths:
             if not os.path.isfile(file_path):
-                print "File %s not found." % file_path
+                print("File %s not found." % file_path)
                 continue
-            f = file(file_path, 'r')
+            f = open(file_path, 'r')
             data = f.readlines()
             f.close()
 
diff --git a/categories/migration.py b/categories/migration.py
index 77b061b..57b2788 100644
--- a/categories/migration.py
+++ b/categories/migration.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
+
 
 from django.db import connection, transaction
 from django.apps import apps
@@ -47,7 +47,7 @@ def migrate_app(sender, *args, **kwargs):
 
     app_name = app_config.label
 
-    fields = [fld for fld in registry._field_registry.keys() if fld.startswith(app_name)]
+    fields = [fld for fld in list(registry._field_registry.keys()) if fld.startswith(app_name)]
 
     sid = transaction.savepoint()
     for fld in fields:
diff --git a/categories/migrations/0001_initial.py b/categories/migrations/0001_initial.py
index 207a589..ffd6beb 100644
--- a/categories/migrations/0001_initial.py
+++ b/categories/migrations/0001_initial.py
@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
+
 
 from django.db import models, migrations
 import django.core.files.storage
@@ -20,15 +20,15 @@ class Migration(migrations.Migration):
                 ('name', models.CharField(max_length=100, verbose_name='name')),
                 ('slug', models.SlugField(verbose_name='slug')),
                 ('active', models.BooleanField(default=True, verbose_name='active')),
-                ('thumbnail', models.FileField(storage=django.core.files.storage.FileSystemStorage(), null=True, upload_to=b'uploads/categories/thumbnails', blank=True)),
+                ('thumbnail', models.FileField(storage=django.core.files.storage.FileSystemStorage(), null=True, upload_to='uploads/categories/thumbnails', blank=True)),
                 ('thumbnail_width', models.IntegerField(null=True, blank=True)),
                 ('thumbnail_height', models.IntegerField(null=True, blank=True)),
                 ('order', models.IntegerField(default=0)),
-                ('alternate_title', models.CharField(default=b'', help_text=b'An alternative title to use on pages with this category.', max_length=100, blank=True)),
-                ('alternate_url', models.CharField(help_text=b'An alternative URL to use instead of the one derived from the category hierarchy.', max_length=200, blank=True)),
+                ('alternate_title', models.CharField(default='', help_text='An alternative title to use on pages with this category.', max_length=100, blank=True)),
+                ('alternate_url', models.CharField(help_text='An alternative URL to use instead of the one derived from the category hierarchy.', max_length=200, blank=True)),
                 ('description', models.TextField(null=True, blank=True)),
-                ('meta_keywords', models.CharField(default=b'', help_text=b'Comma-separated keywords for search engines.', max_length=255, blank=True)),
-                ('meta_extra', models.TextField(default=b'', help_text=b'(Advanced) Any additional HTML to be placed verbatim in the &lt;head&gt;', blank=True)),
+                ('meta_keywords', models.CharField(default='', help_text='Comma-separated keywords for search engines.', max_length=255, blank=True)),
+                ('meta_extra', models.TextField(default='', help_text='(Advanced) Any additional HTML to be placed verbatim in the &lt;head&gt;', blank=True)),
                 ('lft', models.PositiveIntegerField(editable=False, db_index=True)),
                 ('rght', models.PositiveIntegerField(editable=False, db_index=True)),
                 ('tree_id', models.PositiveIntegerField(editable=False, db_index=True)),
@@ -47,7 +47,7 @@ class Migration(migrations.Migration):
             fields=[
                 ('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=b'200', null=True, verbose_name='relation type', blank=True)),
+                ('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')),
             ],
diff --git a/categories/models.py b/categories/models.py
index 7383195..1921cfe 100644
--- a/categories/models.py
+++ b/categories/models.py
@@ -1,7 +1,8 @@
 from django.core.urlresolvers import reverse
 from django.db import models
-from django.utils.encoding import force_unicode
+from django.utils.encoding import force_text
 from django.contrib.contenttypes.models import ContentType
+from functools import reduce
 try:
     from django.contrib.contenttypes.fields import GenericForeignKey
 except ImportError:
@@ -63,7 +64,7 @@ class Category(CategoryBase):
         except NoReverseMatch:
             prefix = '/'
         ancestors = list(self.get_ancestors()) + [self, ]
-        return prefix + '/'.join([force_unicode(i.slug) for i in ancestors]) + '/'
+        return prefix + '/'.join([force_text(i.slug) for i in ancestors]) + '/'
 
     if RELATION_MODELS:
         def get_related_content_type(self, content_type):
@@ -133,7 +134,7 @@ class CategoryRelation(models.Model):
     object_id = models.PositiveIntegerField(verbose_name=_('object id'))
     content_object = GenericForeignKey('content_type', 'object_id')
     relation_type = models.CharField(verbose_name=_('relation type'),
-        max_length="200",
+        max_length=200,
         blank=True,
         null=True,
         help_text=_("A generic text field to tag a relation, like 'leadphoto'."))
@@ -141,7 +142,7 @@ class CategoryRelation(models.Model):
     objects = CategoryRelationManager()
 
     def __unicode__(self):
-        return u"CategoryRelation"
+        return "CategoryRelation"
 
 try:
     from south.db import db  # South is required for migrating. Need to check for it
diff --git a/categories/registration.py b/categories/registration.py
index 6631f70..ad307cd 100644
--- a/categories/registration.py
+++ b/categories/registration.py
@@ -2,7 +2,7 @@
 These functions handle the adding of fields to other models
 """
 from django.db.models import FieldDoesNotExist, ForeignKey, ManyToManyField
-import fields
+from . import fields
 # from settings import self._field_registry, self._model_registry
 from django.utils.translation import ugettext_lazy as _
 from django.core.exceptions import ImproperlyConfigured
@@ -32,7 +32,7 @@ class Registry(object):
 
         app_label = app
 
-        if isinstance(field_definitions, basestring):
+        if isinstance(field_definitions, str):
             field_definitions = [field_definitions]
         elif not isinstance(field_definitions, collections.Iterable):
             raise ImproperlyConfigured(_('Field configuration for %(app)s should '
@@ -64,7 +64,7 @@ class Registry(object):
             extra_params = {'to': 'categories.Category', 'blank': True}
             if field_type != 'ManyToManyField':
                 extra_params['null'] = True
-            if isinstance(fld, basestring):
+            if isinstance(fld, str):
                 field_name = fld
             elif isinstance(fld, dict):
                 if 'name' in fld:
@@ -119,15 +119,15 @@ def _process_registry(registry, call_func):
     Given a dictionary, and a registration function, process the registry
     """
     from django.core.exceptions import ImproperlyConfigured
-    from django.db.models.loading import get_model
+    from django.apps import apps
 
-    for key, value in registry.items():
-        model = get_model(*key.split('.'))
+    for key, value in list(registry.items()):
+        model = apps.get_model(*key.split('.'))
         if model is None:
             raise ImproperlyConfigured(_('%(key)s is not a model') % {'key': key})
         if isinstance(value, (tuple, list)):
             for item in value:
-                if isinstance(item, basestring):
+                if isinstance(item, str):
                     call_func(model, item)
                 elif isinstance(item, dict):
                     field_name = item.pop('name')
@@ -135,7 +135,7 @@ def _process_registry(registry, call_func):
                 else:
                     raise ImproperlyConfigured(_("%(settings)s doesn't recognize the value of %(key)s") %
                                                {'settings': 'CATEGORY_SETTINGS', 'key': key})
-        elif isinstance(value, basestring):
+        elif isinstance(value, str):
             call_func(model, value)
         elif isinstance(value, dict):
             field_name = value.pop('name')
diff --git a/categories/settings.py b/categories/settings.py
index 2d1589d..b3d8d51 100644
--- a/categories/settings.py
+++ b/categories/settings.py
@@ -1,6 +1,7 @@
 from django.conf import settings
 from django.db.models import Q
 from django.utils.translation import ugettext_lazy as _
+import collections
 
 DEFAULT_SETTINGS = {
     'ALLOW_SLUG_CHANGE': False,
@@ -18,9 +19,9 @@ DEFAULT_SETTINGS = {
 DEFAULT_SETTINGS.update(getattr(settings, 'CATEGORIES_SETTINGS', {}))
 
 if DEFAULT_SETTINGS['SLUG_TRANSLITERATOR']:
-    if callable(DEFAULT_SETTINGS['SLUG_TRANSLITERATOR']):
+    if isinstance(DEFAULT_SETTINGS['SLUG_TRANSLITERATOR'], collections.Callable):
         pass
-    elif isinstance(DEFAULT_SETTINGS['SLUG_TRANSLITERATOR'], basestring):
+    elif isinstance(DEFAULT_SETTINGS['SLUG_TRANSLITERATOR'], str):
         from django.utils.importlib import import_module
         bits = DEFAULT_SETTINGS['SLUG_TRANSLITERATOR'].split(".")
         module = import_module(".".join(bits[:-1]))
diff --git a/categories/south_migration.py b/categories/south_migration.py
index 431cbe0..9ce9bcf 100644
--- a/categories/south_migration.py
+++ b/categories/south_migration.py
@@ -11,22 +11,22 @@ def migrate_app(sender, app, created_models=None, verbosity=False, *args, **kwar
     from .models import Category
     from .registration import registry
     import sys
-    import StringIO
+    import io
 
     org_stderror = sys.stderr
-    sys.stderr = StringIO.StringIO()  # south will print out errors to stderr
+    sys.stderr = io.StringIO()  # south will print out errors to stderr
     try:
         from south.db import db
     except ImportError:
         raise ImproperlyConfigured(_('%(dependency)s must be installed for this command to work') %
                                    {'dependency': 'South'})
     # pull the information from the registry
-    if isinstance(app, basestring):
+    if isinstance(app, str):
         app_name = app
     else:
         app_name = app.__name__.split('.')[-2]
 
-    fields = [fld for fld in registry._field_registry.keys() if fld.startswith(app_name)]
+    fields = [fld for fld in list(registry._field_registry.keys()) if fld.startswith(app_name)]
     # call the south commands to add the fields/tables
     for fld in fields:
         app_name, model_name, field_name = fld.split('.')
@@ -43,14 +43,14 @@ def migrate_app(sender, app, created_models=None, verbosity=False, *args, **kwar
                 db.add_column(table_name, field_name, registry._field_registry[fld], keep_default=False)
                 db.commit_transaction()
                 if verbosity:
-                    print (_('Added ForeignKey %(field_name)s to %(model_name)s') %
-                           {'field_name': field_name, 'model_name': model_name})
-            except DatabaseError, e:
+                    print((_('Added ForeignKey %(field_name)s to %(model_name)s') %
+                           {'field_name': field_name, 'model_name': model_name}))
+            except DatabaseError as e:
                 db.rollback_transaction()
                 if "already exists" in str(e):
                     if verbosity > 1:
-                        print (_('ForeignKey %(field_name)s to %(model_name)s already exists') %
-                               {'field_name': field_name, 'model_name': model_name})
+                        print((_('ForeignKey %(field_name)s to %(model_name)s already exists') %
+                               {'field_name': field_name, 'model_name': model_name}))
                 else:
                     sys.stderr = org_stderror
                     raise e
@@ -66,14 +66,14 @@ def migrate_app(sender, app, created_models=None, verbosity=False, *args, **kwar
                 db.create_unique(table_name, ['%s_id' % model_name, 'category_id'])
                 db.commit_transaction()
                 if verbosity:
-                    print (_('Added Many2Many table between %(model_name)s and %(category_table)s') %
-                           {'model_name': model_name, 'category_table': 'category'})
-            except DatabaseError, e:
+                    print((_('Added Many2Many table between %(model_name)s and %(category_table)s') %
+                           {'model_name': model_name, 'category_table': 'category'}))
+            except DatabaseError as e:
                 db.rollback_transaction()
                 if "already exists" in str(e):
                     if verbosity > 1:
-                        print (_('Many2Many table between %(model_name)s and %(category_table)s already exists') %
-                               {'model_name': model_name, 'category_table': 'category'})
+                        print((_('Many2Many table between %(model_name)s and %(category_table)s already exists') %
+                               {'model_name': model_name, 'category_table': 'category'}))
                 else:
                     sys.stderr = org_stderror
                     raise e
@@ -98,23 +98,23 @@ def drop_field(app_name, model_name, field_name):
     fld = '%s.%s.%s' % (app_name, model_name, field_name)
 
     if isinstance(registry._field_registry[fld], CategoryFKField):
-        print (_('Dropping ForeignKey %(field_name)s from %(model_name)s') %
-               {'field_name': field_name, 'model_name': model_name})
+        print((_('Dropping ForeignKey %(field_name)s from %(model_name)s') %
+               {'field_name': field_name, 'model_name': model_name}))
         try:
             db.start_transaction()
             table_name = mdl._meta.db_table
             db.delete_column(table_name, field_name)
             db.commit_transaction()
-        except DatabaseError, e:
+        except DatabaseError as e:
             db.rollback_transaction()
             raise e
     elif isinstance(registry._field_registry[fld], CategoryM2MField):
-        print (_('Dropping Many2Many table between %(model_name)s and %(category_table)s') %
-               {'model_name': model_name, 'category_table': 'category'})
+        print((_('Dropping Many2Many table between %(model_name)s and %(category_table)s') %
+               {'model_name': model_name, 'category_table': 'category'}))
         try:
             db.start_transaction()
             db.delete_table(table_name, cascade=False)
             db.commit_transaction()
-        except DatabaseError, e:
+        except DatabaseError as e:
             db.rollback_transaction()
             raise e
diff --git a/categories/templatetags/category_tags.py b/categories/templatetags/category_tags.py
index f21a42a..1617b26 100644
--- a/categories/templatetags/category_tags.py
+++ b/categories/templatetags/category_tags.py
@@ -1,7 +1,8 @@
 from django import template
-from django.db.models import get_model
+from django.apps import apps
 from django.template import (Node, TemplateSyntaxError, VariableDoesNotExist)
 from django.template.base import FilterExpression
+from django.utils.six import string_types
 from categories.base import CategoryBase
 from categories.models import Category
 from mptt.utils import drilldown_tree_for_node
@@ -30,8 +31,8 @@ def get_cat_model(model):
     Return a class from a string or class
     """
     try:
-        if isinstance(model, basestring):
-            model_class = get_model(*model.split("."))
+        if isinstance(model, string_types):
+            model_class = apps.get_model(*model.split("."))
         elif issubclass(model, CategoryBase):
             model_class = model
         if model_class is None:
@@ -119,13 +120,13 @@ def get_category_drilldown(parser, token):
                 '{%% %(tagname)s category_obj as varname %%}.'
     if len(bits) == 4:
         if bits[2] != 'as':
-            raise template.TemplateSyntaxError, error_str % {'tagname': bits[0]}
+            raise template.TemplateSyntaxError(error_str % {'tagname': bits[0]})
         if bits[2] == 'as':
             varname = bits[3].strip("'\"")
             model = "categories.category"
     if len(bits) == 6:
         if bits[2] not in ('using', 'as') or bits[4] not in ('using', 'as'):
-            raise template.TemplateSyntaxError, error_str % {'tagname': bits[0]}
+            raise template.TemplateSyntaxError(error_str % {'tagname': bits[0]})
         if bits[2] == 'as':
             varname = bits[3].strip("'\"")
             model = bits[5].strip("'\"")
@@ -266,7 +267,7 @@ def get_top_level_categories(parser, token):
 
 def get_latest_objects_by_category(category, app_label, model_name, set_name,
                                     date_field='pub_date', num=15):
-    m = get_model(app_label, model_name)
+    m = apps.get_model(app_label, model_name)
     if not isinstance(category, CategoryBase):
         category = Category.objects.get(slug=str(category))
     children = category.children.all()
diff --git a/categories/tests/test_category_import.py b/categories/tests/test_category_import.py
index fd83864..8384add 100644
--- a/categories/tests/test_category_import.py
+++ b/categories/tests/test_category_import.py
@@ -3,12 +3,16 @@
 # test mixed
 import os
 
-from django.test import TestCase
+from django.conf import settings
+from django.test import TestCase, override_settings
 from categories.models import Category
 from categories.management.commands.import_categories import Command
 from django.core.management.base import CommandError
 
+from categories.registration import _process_registry, registry
 
+
+@override_settings(INSTALLED_APPS=(app for app in settings.INSTALLED_APPS if app != 'django.contrib.flatpages'))
 class CategoryImportTest(TestCase):
     def setUp(self):
         pass
diff --git a/categories/tests/test_registration.py b/categories/tests/test_registration.py
index 945916e..c4259d0 100644
--- a/categories/tests/test_registration.py
+++ b/categories/tests/test_registration.py
@@ -19,7 +19,7 @@ class CategoryRegistrationTest(TestCase):
         }
         _process_registry(FK_REGISTRY, registry.register_fk)
         from django.contrib.flatpages.models import FlatPage
-        self.assertTrue('category' in FlatPage()._meta.get_all_field_names())
+        self.assertTrue('category' in [f.name for f in FlatPage()._meta.get_fields()])
 
     def test_foreignkey_dict(self):
         FK_REGISTRY = {
@@ -27,7 +27,7 @@ class CategoryRegistrationTest(TestCase):
         }
         _process_registry(FK_REGISTRY, registry.register_fk)
         from django.contrib.flatpages.models import FlatPage
-        self.assertTrue('category' in FlatPage()._meta.get_all_field_names())
+        self.assertTrue('category' in [f.name for f in FlatPage()._meta.get_fields()])
 
     def test_foreignkey_list(self):
         FK_REGISTRY = {
@@ -37,13 +37,13 @@ class CategoryRegistrationTest(TestCase):
         }
         _process_registry(FK_REGISTRY, registry.register_fk)
         from django.contrib.flatpages.models import FlatPage
-        self.assertTrue('category' in FlatPage()._meta.get_all_field_names())
+        self.assertTrue('category' in [f.name for f in FlatPage()._meta.get_fields()])
 
     if django.VERSION[1] >= 7:
         def test_new_foreignkey_string(self):
             registry.register_model('flatpages', 'flatpage', 'ForeignKey', 'category')
             from django.contrib.flatpages.models import FlatPage
-            self.assertTrue('category' in FlatPage()._meta.get_all_field_names())
+            self.assertTrue('category' in [f.name for f in FlatPage()._meta.get_fields()])
 
 
 class Categorym2mTest(TestCase):
@@ -53,6 +53,6 @@ class Categorym2mTest(TestCase):
         }
         _process_registry(M2M_REGISTRY, registry.register_m2m)
         from django.contrib.flatpages.models import FlatPage
-        self.assertTrue('category' in FlatPage()._meta.get_all_field_names())
+        self.assertTrue('category' in [f.name for f in FlatPage()._meta.get_fields()])
 
 
diff --git a/categories/tests/test_templatetags.py b/categories/tests/test_templatetags.py
index 1ec8a80..526157f 100644
--- a/categories/tests/test_templatetags.py
+++ b/categories/tests/test_templatetags.py
@@ -28,40 +28,40 @@ class CategoryTagsTest(TestCase):
         Test that we can properly retrieve a category.
         """
         # display_path_as_ul
-        rock_resp = u'<ul><li><a href="/categories/">Top</a></li></ul>'
+        rock_resp = '<ul><li><a href="/categories/">Top</a></li></ul>'
         resp = self.render_template('{% load category_tags %}{% display_path_as_ul "/Rock" %}')
         resp = re.sub(r'\n$', "", resp)
         self.assertEqual(resp, rock_resp)
 
         # display_drilldown_as_ul
-        expected_resp = u'<ul><li><a href="/categories/">Top</a><ul><li><a href="/categories/world/">World</a><ul><li><strong>Worldbeat</strong><ul><li><a href="/categories/world/worldbeat/afrobeat/">Afrobeat</a></li></ul></li></ul></li></ul></li></ul>'
+        expected_resp = '<ul><li><a href="/categories/">Top</a><ul><li><a href="/categories/world/">World</a><ul><li><strong>Worldbeat</strong><ul><li><a href="/categories/world/worldbeat/afrobeat/">Afrobeat</a></li></ul></li></ul></li></ul></li></ul>'
         resp = self.render_template('{% load category_tags %}'
             '{% display_drilldown_as_ul "/World/Worldbeat" "categories.category" %}')
         resp = re.sub(r'\n$', "", resp)
         self.assertEqual(resp, expected_resp)
 
         # breadcrumbs
-        expected_resp = u'<a href="/categories/world/">World</a> &gt; Worldbeat'
+        expected_resp = '<a href="/categories/world/">World</a> &gt; Worldbeat'
         resp = self.render_template('{% load category_tags %}'
             '{% breadcrumbs "/World/Worldbeat" " &gt; " "categories.category" %}')
         self.assertEqual(resp, expected_resp)
 
         # get_top_level_categories
-        expected_resp = u'Avant-garde|Blues|Country|Easy listening|Electronic|Hip hop/Rap music|Jazz|Latin|Modern folk|Pop|Reggae|Rhythm and blues|Rock|World|'
+        expected_resp = 'Avant-garde|Blues|Country|Easy listening|Electronic|Hip hop/Rap music|Jazz|Latin|Modern folk|Pop|Reggae|Rhythm and blues|Rock|World|'
         resp = self.render_template('{% load category_tags %}'
             '{% get_top_level_categories using "categories.category" as varname %}'
             '{% for item in varname %}{{ item }}|{% endfor %}')
         self.assertEqual(resp, expected_resp)
 
         # get_category_drilldown
-        expected_resp = u"World|World &gt; Worldbeat|"
+        expected_resp = "World|World &gt; Worldbeat|"
         resp = self.render_template('{% load category_tags %}'
             '{% get_category_drilldown "/World" using "categories.category" as var %}'
             '{% for item in var %}{{ item }}|{% endfor %}')
         self.assertEqual(resp, expected_resp)
 
         # recursetree
-        expected_resp = u'<ul><li>Country<ul><li>Country pop<ul><li>Urban Cowboy</li></ul></li></ul></li><li>World<ul><li>Worldbeat<ul></ul></li></ul></li></ul>'
+        expected_resp = '<ul><li>Country<ul><li>Country pop<ul><li>Urban Cowboy</li></ul></li></ul></li><li>World<ul><li>Worldbeat<ul></ul></li></ul></li></ul>'
         ctxt = {'nodes': Category.objects.filter(name__in=("Worldbeat", "Urban Cowboy"))}
         resp = self.render_template('{% load category_tags %}'
             '<ul>{% recursetree nodes|tree_queryset %}<li>{{ node.name }}'
diff --git a/categories/urls.py b/categories/urls.py
index 333c6b7..c666c62 100644
--- a/categories/urls.py
+++ b/categories/urls.py
@@ -1,5 +1,6 @@
-from django.conf.urls import patterns, url
+from django.conf.urls import url
 from .models import Category
+from . import views
 
 try:
     from django.views.generic import DetailView, ListView
@@ -15,12 +16,12 @@ categorytree_dict = {
     'queryset': Category.objects.filter(level=0)
 }
 
-urlpatterns = patterns('',
+urlpatterns = (
     url(
         r'^$', ListView.as_view(**categorytree_dict), name='categories_tree_list'
     ),
 )
 
-urlpatterns += patterns('categories.views',
-    url(r'^(?P<path>.+)/$', 'category_detail', name='categories_category'),
+urlpatterns += (
+    url(r'^(?P<path>.+)/$', views.category_detail, name='categories_category'),
 )
diff --git a/categories/views.py b/categories/views.py
index 9d5d383..21311d6 100644
--- a/categories/views.py
+++ b/categories/views.py
@@ -63,14 +63,14 @@ class CategoryDetailView(DetailView):
 
     def get_object(self, **kwargs):
         if self.path_field not in self.kwargs:
-            raise AttributeError(u"Category detail view %s must be called with "
-                                 u"a %s." % self.__class__.__name__, self.path_field)
+            raise AttributeError("Category detail view %s must be called with "
+                                 "a %s." % self.__class__.__name__, self.path_field)
         if self.queryset is None:
             queryset = self.get_queryset()
         try:
             return get_category_for_path(self.kwargs[self.path_field], self.model.objects.all())
         except ObjectDoesNotExist:
-            raise Http404(_(u"No %(verbose_name)s found matching the query") %
+            raise Http404(_("No %(verbose_name)s found matching the query") %
                           {'verbose_name': queryset.model._meta.verbose_name})
 
     def get_template_names(self):
diff --git a/doc_src/conf.py b/doc_src/conf.py
index 51ac114..5773732 100644
--- a/doc_src/conf.py
+++ b/doc_src/conf.py
@@ -40,8 +40,8 @@ source_suffix = '.rst'
 master_doc = 'index'
 
 # General information about the project.
-project = u'Django Categories'
-copyright = u'2010-2012, Corey Oordt'
+project = 'Django Categories'
+copyright = '2010-2012, Corey Oordt'
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
@@ -175,8 +175,8 @@ htmlhelp_basename = 'DjangoCategoriesdoc'
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title, author, documentclass [howto/manual]).
 latex_documents = [
-  ('index', 'DjangoCategories.tex', u'Django Categories Documentation',
-   u'CoreyOordt', 'manual'),
+  ('index', 'DjangoCategories.tex', 'Django Categories Documentation',
+   'CoreyOordt', 'manual'),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
diff --git a/example/settings-testing.py b/example/settings-testing.py
index db71853..d375b93 100644
--- a/example/settings-testing.py
+++ b/example/settings-testing.py
@@ -7,7 +7,6 @@ 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)
 DEBUG = True
-TEMPLATE_DEBUG = DEBUG
 
 ADMINS = (
     # ('Your Name', 'your_email@domain.com'),
@@ -66,11 +65,6 @@ STATICFILES_FINDERS = (
 
 SECRET_KEY = 'bwq#m)-zsey-fs)0#4*o=2z(v5g!ei=zytl9t-1hesh4b&-u^d'
 
-TEMPLATE_LOADERS = (
-    'django.template.loaders.filesystem.Loader',
-    'django.template.loaders.app_directories.Loader',
-)
-
 MIDDLEWARE_CLASSES = (
     'django.middleware.common.CommonMiddleware',
     'django.contrib.sessions.middleware.SessionMiddleware',
@@ -81,9 +75,16 @@ MIDDLEWARE_CLASSES = (
 
 ROOT_URLCONF = 'urls'
 
-TEMPLATE_DIRS = (
-    os.path.abspath(os.path.join(os.path.dirname(__file__), 'templates')),
-)
+TEMPLATES = [
+    {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'APP_DIRS': True,
+        'DIRS': [os.path.abspath(os.path.join(os.path.dirname(__file__), 'templates'))],
+        'OPTIONS': {
+            'debug': DEBUG,
+        }
+    },
+]
 
 if django.VERSION[1] > 5:
     TEST_RUNNER = 'django.test.runner.DiscoverRunner'
diff --git a/example/simpletext/admin.py b/example/simpletext/admin.py
index 55a5d73..9060c31 100644
--- a/example/simpletext/admin.py
+++ b/example/simpletext/admin.py
@@ -1,4 +1,4 @@
-from models import SimpleText, SimpleCategory
+from .models import SimpleText, SimpleCategory
 from django.contrib import admin
 
 from categories.admin import CategoryBaseAdmin, CategoryBaseAdminForm
diff --git a/example/simpletext/tests.py b/example/simpletext/tests.py
index 2247054..c7c4668 100755
--- a/example/simpletext/tests.py
+++ b/example/simpletext/tests.py
@@ -12,7 +12,7 @@ class SimpleTest(TestCase):
         """
         Tests that 1 + 1 always equals 2.
         """
-        self.failUnlessEqual(1 + 1, 2)
+        self.assertEqual(1 + 1, 2)
 
 __test__ = {"doctest": """
 Another way to test that 1 + 1 is equal to 2.
diff --git a/example/urls.py b/example/urls.py
index a15924d..d19d430 100644
--- a/example/urls.py
+++ b/example/urls.py
@@ -1,7 +1,9 @@
-from django.conf.urls import patterns, include
+from django.conf.urls import include, url
 
 # Uncomment the next two lines to enable the admin:
 from django.contrib import admin
+from django.views.static import serve
+
 admin.autodiscover()
 
 
@@ -9,7 +11,7 @@ import os
 
 ROOT_PATH = os.path.dirname(os.path.dirname(__file__))
 
-urlpatterns = patterns('',
+urlpatterns = (
     # Example:
     # (r'^sample/', include('sample.foo.urls')),
 
@@ -18,18 +20,18 @@ urlpatterns = patterns('',
     # (r'^admin/doc/', include('django.contrib.admindocs.urls')),
 
     # Uncomment the next line to enable the admin:
-    (r'^admin/', include(admin.site.urls)),
-    (r'^categories/', include('categories.urls')),
+    url(r'^admin/', include(admin.site.urls)),
+    url(r'^categories/', include('categories.urls')),
     #(r'^cats/', include('categories.urls')),
 
-    (r'^static/categories/(?P<path>.*)$', 'django.views.static.serve',
+    url(r'^static/categories/(?P<path>.*)$', serve,
         {'document_root': ROOT_PATH + '/categories/media/categories/'}),
 
     # (r'^static/editor/(?P<path>.*)$', 'django.views.static.serve',
     #     {'document_root': ROOT_PATH + '/editor/media/editor/',
     #      'show_indexes':True}),
 
-     (r'^static/(?P<path>.*)$', 'django.views.static.serve',
+    url(r'^static/(?P<path>.*)$', serve,
          {'document_root': os.path.join(ROOT_PATH, 'example', 'static')}),
 
 )
diff --git a/requirements.txt b/requirements.txt
index 38a3a73..be1d646 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,2 @@
-django-mptt>=0.6,<0.7
+django-mptt>=0.8,<0.9
 unicode-slugify==0.1.1
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 0000000..32fb129
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,14 @@
+[tox]
+envlist =
+    py27-django{18,19},
+    py34-django{18,19},
+    py35-django{18,19},
+
+[testenv]
+deps=
+    django19: Django==1.9.2
+    django18: Django==1.8.9
+    -r{toxinidir}/requirements.txt
+
+commands=
+  {toxinidir}/example/manage.py test --settings='settings-testing' categories