diff --git a/.gitignore b/.gitignore
index 2267b36..f881ed8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+*~
 *.swp
 *.pyc
 *.db
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..18a193c
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,46 @@
+sudo: false
+language: python
+cache: pip
+
+matrix:
+  include:
+    - python: 2.7
+      env: DJANGO="Django>=1.8,<1.9"
+    - python: 3.2
+      env: DJANGO="Django>=1.8,<1.9"
+    - python: 3.3
+      env: DJANGO="Django>=1.8,<1.9"
+    - python: 3.4
+      env: DJANGO="Django>=1.8,<1.9"
+    - python: 3.5
+      env: DJANGO="Django>=1.8,<1.9"
+    - python: 2.7
+      env: DJANGO="Django>=1.9,<1.10"
+    - python: 3.4
+      env: DJANGO="Django>=1.9,<1.10"
+    - python: 3.5
+      env: DJANGO="Django>=1.9,<1.10"
+    - python: 2.7
+      env: DJANGO="Django>=1.10,<1.11"
+    - python: 3.4
+      env: DJANGO="Django>=1.10,<1.11"
+    - python: 3.5
+      env: DJANGO="Django>=1.10,<1.11"
+    - python: 2.7
+      env: DJANGO="Django>=1.11,<2.0"
+    - python: 3.4
+      env: DJANGO="Django>=1.11,<2.0"
+    - python: 3.5
+      env: DJANGO="Django>=1.11,<2.0"
+    - python: 3.6
+      env: DJANGO="Django>=1.11,<2.0"
+
+install:
+ - pip install $DJANGO
+ - pip install flake8
+ - pip install -e .
+
+before_script:
+  - flake8
+
+script: ./runtests.sh
diff --git a/examples/protected_downloads/download/admin.py b/examples/protected_downloads/download/admin.py
index 617ee11..ca4c0b3 100644
--- a/examples/protected_downloads/download/admin.py
+++ b/examples/protected_downloads/download/admin.py
@@ -3,7 +3,6 @@
 from .models import Download
 
 
+@admin.register(Download)
 class DownloadAdmin(admin.ModelAdmin):
     list_display = ['title', 'file']
-
-admin.site.register(Download, DownloadAdmin)
diff --git a/examples/protected_downloads/download/models.py b/examples/protected_downloads/download/models.py
index 0e10dbc..2ca74b2 100644
--- a/examples/protected_downloads/download/models.py
+++ b/examples/protected_downloads/download/models.py
@@ -1,8 +1,8 @@
-from django.db import models
-
-from django.contrib.auth.models import User
 from django.conf import settings
+from django.contrib.auth.models import User
 from django.core.files.storage import FileSystemStorage
+from django.db import models
+from django.urls import reverse
 
 sendfile_storage = FileSystemStorage(location=settings.SENDFILE_ROOT)
 
@@ -17,9 +17,8 @@ class Download(models.Model):
     def is_user_allowed(self, user):
         return self.users.filter(pk=user.pk).exists()
 
-    def __unicode__(self):
+    def __str__(self):
         return self.title
 
-    @models.permalink
     def get_absolute_url(self):
-        return ('download', [self.pk], {})
+        return reverse('download', [self.pk], {})
diff --git a/examples/protected_downloads/download/tests.py b/examples/protected_downloads/download/tests.py
deleted file mode 100644
index 501deb7..0000000
--- a/examples/protected_downloads/download/tests.py
+++ /dev/null
@@ -1,16 +0,0 @@
-"""
-This file demonstrates writing tests using the unittest module. These will pass
-when you run "manage.py test".
-
-Replace this with more appropriate tests for your application.
-"""
-
-from django.test import TestCase
-
-
-class SimpleTest(TestCase):
-    def test_basic_addition(self):
-        """
-        Tests that 1 + 1 always equals 2.
-        """
-        self.assertEqual(1 + 1, 2)
diff --git a/examples/protected_downloads/download/urls.py b/examples/protected_downloads/download/urls.py
index fd4bb28..8188e4c 100644
--- a/examples/protected_downloads/download/urls.py
+++ b/examples/protected_downloads/download/urls.py
@@ -1,8 +1,8 @@
-from django.conf.urls.defaults import *
+from django.conf.urls import url
 
 from .views import download, download_list
 
-urlpatterns = patterns('',
+urlpatterns = [
     url(r'^$', download_list),
     url(r'(?P<download_id>\d+)/$', download, name='download'),
-)
+]
diff --git a/examples/protected_downloads/download/views.py b/examples/protected_downloads/download/views.py
index e99b6bc..e49c4ff 100644
--- a/examples/protected_downloads/download/views.py
+++ b/examples/protected_downloads/download/views.py
@@ -1,8 +1,7 @@
 from django.contrib.auth.decorators import login_required
-from django.shortcuts import get_object_or_404, render_to_response
-from django.http import HttpResponseForbidden
 from django.db.models import Q
-from django.template import RequestContext
+from django.http import HttpResponseForbidden
+from django.shortcuts import get_object_or_404, render
 
 from sendfile import sendfile
 
@@ -29,6 +28,4 @@ def download_list(request):
         downloads = downloads.filter(Q(is_public=True) | Q(users=request.user))
     else:
         downloads = downloads.filter(is_public=True)
-    return render_to_response('download/download_list.html',
-                              {'download_list': downloads},
-                              context_instance=RequestContext(request))
+    return render(request, 'download/download_list.html', {'download_list': downloads})
diff --git a/examples/protected_downloads/manage.py b/examples/protected_downloads/manage.py
old mode 100644
new mode 100755
index 3e098b0..d9295d1
--- a/examples/protected_downloads/manage.py
+++ b/examples/protected_downloads/manage.py
@@ -1,14 +1,10 @@
 #!/usr/bin/env python
+import os
+import sys
 
-from __future__ import absolute_import
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
-from django.core.management import execute_manager
-try:
-    from . import settings  # Assumed to be in the same directory.
-except ImportError:
-    import sys
-    sys.stderr.write("Error: Can't find the file 'settings.py' in the directory containing %r. It appears you've customized things.\nYou'll have to run django-admin.py, passing it your settings module.\n(If the file settings.py does indeed exist, it's causing an ImportError somehow.)\n" % __file__)
-    sys.exit(1)
-
-if __name__ == "__main__":
-    execute_manager(settings)
+if __name__ == '__main__':
+    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'protected_downloads.settings')
+    from django.core.management import execute_from_command_line
+    execute_from_command_line(sys.argv)
diff --git a/examples/protected_downloads/settings.py b/examples/protected_downloads/settings.py
index 245739c..5f507db 100644
--- a/examples/protected_downloads/settings.py
+++ b/examples/protected_downloads/settings.py
@@ -2,91 +2,83 @@
 
 import os.path
 
+BASE_DIR = os.path.dirname(os.path.abspath(__file__))
+
+SECRET_KEY = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890'
+
 DEBUG = True
-TEMPLATE_DEBUG = DEBUG
 
-ADMINS = (
-    # ('Your Name', 'your_email@domain.com'),
-)
+ALLOWED_HOSTS = []
+
+
+# Application definition
+
+INSTALLED_APPS = [
+    'django.contrib.auth',
+    'django.contrib.contenttypes',
+    'django.contrib.sessions',
+    'django.contrib.admin',
+    'protected_downloads.download',
+]
+
+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',
+]
 
-MANAGERS = ADMINS
+ROOT_URLCONF = 'protected_downloads.urls'
 
-PROJECT_ROOT = os.path.dirname(os.path.abspath(__file__))
+TEMPLATES = [
+    {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'DIRS': [os.path.join(BASE_DIR, 'templates')],
+        'OPTIONS': {
+            'context_processors': [
+                'django.template.context_processors.debug',
+                'django.template.context_processors.request',
+                'django.contrib.auth.context_processors.auth',
+                'django.contrib.messages.context_processors.messages',
+            ],
+        },
+    },
+]
 
 DATABASES = {
     'default': {
         'ENGINE': 'django.db.backends.sqlite3',
-        'NAME': os.path.join(PROJECT_ROOT, 'download.db'),
+        'NAME': os.path.join(BASE_DIR, 'download.db'),
     }
 }
 
-# Local time zone for this installation. Choices can be found here:
-# http://en.wikipedia.org/wiki/List_of_tz_zones_by_name
-# although not all choices may be available on all operating systems.
-# If running in a Windows environment this must be set to the same as your
-# system time zone.
-TIME_ZONE = 'America/Chicago'
 
-# Language code for this installation. All choices can be found here:
-# http://www.i18nguy.com/unicode/language-identifiers.html
-LANGUAGE_CODE = 'en-us'
+# Internationalization
 
-SITE_ID = 1
+TIME_ZONE = 'UTC'
 
-# If you set this to False, Django will make some optimizations so as not
-# to load the internationalization machinery.
 USE_I18N = True
 
-# Absolute path to the directory that holds media.
-# Example: "/home/media/media.lawrence.com/"
-MEDIA_ROOT = ''
-
-# URL that handles the media served from MEDIA_ROOT. Make sure to use a
-# trailing slash if there is a path component (optional in other cases).
-# Examples: "http://media.lawrence.com", "http://example.com/media/"
-MEDIA_URL = ''
+USE_L10N = True
 
-# URL prefix for admin media -- CSS, JavaScript and images. Make sure to use a
-# trailing slash.
-# Examples: "http://foo.com/media/", "/media/".
-ADMIN_MEDIA_PREFIX = '/media/'
+USE_TZ = True
 
-# Make this unique, and don't share it with anybody.
-SECRET_KEY = 'n309^dwk=@+g72ko--8vjyz&1v0u%xf#*0=wzr=2n#f3hb0a=l'
 
-# List of callables that know how to import templates from various sources.
-TEMPLATE_LOADERS = (
-    'django.template.loaders.filesystem.load_template_source',
-    'django.template.loaders.app_directories.load_template_source',
-    # 'django.template.loaders.eggs.load_template_source',
-)
+# Static files (CSS, JavaScript, Images)
 
-MIDDLEWARE_CLASSES = (
-    'django.middleware.common.CommonMiddleware',
-    'django.contrib.sessions.middleware.SessionMiddleware',
-    'django.contrib.auth.middleware.AuthenticationMiddleware',
-)
-
-ROOT_URLCONF = 'protected_downloads.urls'
-
-TEMPLATE_DIRS = (
-    os.path.join(PROJECT_ROOT, 'templates'),
-)
-
-INSTALLED_APPS = (
-    'django.contrib.auth',
-    'django.contrib.contenttypes',
-    'django.contrib.sessions',
-    'django.contrib.sites',
-    'django.contrib.admin',
-    'download',
-    'sendfile',
-)
+STATIC_URL = '/static/'
 
 
 # SENDFILE settings
+# Available backends:
+#   sendfile.backends.development
+#   sendfile.backends.mod_wsgi
+#   sendfile.backends.nginx
+#   sendfile.backends.simple
+#   sendfile.backends.xsendfile
 SENDFILE_BACKEND = 'sendfile.backends.development'
-#SENDFILE_BACKEND = 'sendfile.backends.xsendfile'
-#SENDFILE_BACKEND = 'sendfile.backends.nginx'
-SENDFILE_ROOT = os.path.join(PROJECT_ROOT, 'protected')
+SENDFILE_ROOT = os.path.join(BASE_DIR, 'protected')
 SENDFILE_URL = '/protected'
diff --git a/examples/protected_downloads/urls.py b/examples/protected_downloads/urls.py
index 238d8c7..5ac5804 100644
--- a/examples/protected_downloads/urls.py
+++ b/examples/protected_downloads/urls.py
@@ -1,9 +1,9 @@
-from django.conf.urls.defaults import *
-
+from django.conf.urls import include, url
 from django.contrib import admin
+
 admin.autodiscover()
 
-urlpatterns = patterns('',
-    (r'^', include('protected_downloads.download.urls')),
-    (r'^admin/', include(admin.site.urls)),
-)
+urlpatterns = [
+    url(r'^', include('protected_downloads.download.urls')),
+    url(r'^admin/', admin.site.urls),
+]
diff --git a/runtests.sh b/runtests.sh
new file mode 100755
index 0000000..bcdd5ac
--- /dev/null
+++ b/runtests.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+DJANGO_SETTINGS_MODULE=tests.settings django-admin test tests "$@"
diff --git a/sendfile/__init__.py b/sendfile/__init__.py
index 1cc9809..3125994 100644
--- a/sendfile/__init__.py
+++ b/sendfile/__init__.py
@@ -1,30 +1,31 @@
-VERSION = (0, 3, 11)
-__version__ = '.'.join(map(str, VERSION))
-
 import os.path
 from mimetypes import guess_type
 import unicodedata
+from importlib import import_module
+
+
+VERSION = (0, 3, 11)
+__version__ = '.'.join(map(str, VERSION))
 
 
 def _lazy_load(fn):
     _cached = []
+
     def _decorated():
         if not _cached:
             _cached.append(fn())
         return _cached[0]
+
     def clear():
         while _cached:
             _cached.pop()
     _decorated.clear = clear
+
     return _decorated
 
 
 @_lazy_load
 def _get_sendfile():
-    try:
-        from importlib import import_module
-    except ImportError:
-        from django.utils.importlib import import_module
     from django.conf import settings
     from django.core.exceptions import ImproperlyConfigured
 
@@ -35,7 +36,6 @@ def _get_sendfile():
     return module.sendfile
 
 
-
 def sendfile(request, filename, attachment=False, attachment_filename=None, mimetype=None, encoding=None):
     '''
     create a response to send file using backend configured in SENDFILE_BACKEND
@@ -64,20 +64,16 @@ def sendfile(request, filename, attachment=False, attachment_filename=None, mime
             mimetype = guessed_mimetype
         else:
             mimetype = 'application/octet-stream'
-        
+
     response = _sendfile(request, filename, mimetype=mimetype)
     if attachment:
         if attachment_filename is None:
             attachment_filename = os.path.basename(filename)
         parts = ['attachment']
         if attachment_filename:
-            try:
-                from django.utils.encoding import force_text
-            except ImportError:
-                # Django 1.3
-                from django.utils.encoding import force_unicode as force_text
+            from django.utils.encoding import force_text
             attachment_filename = force_text(attachment_filename)
-            ascii_filename = unicodedata.normalize('NFKD', attachment_filename).encode('ascii','ignore') 
+            ascii_filename = unicodedata.normalize('NFKD', attachment_filename).encode('ascii', 'ignore').decode('ascii')
             parts.append('filename="%s"' % ascii_filename)
             if ascii_filename != attachment_filename:
                 from django.utils.http import urlquote
diff --git a/sendfile/backends/_internalredirect.py b/sendfile/backends/_internalredirect.py
index be4e069..39ec7f3 100644
--- a/sendfile/backends/_internalredirect.py
+++ b/sendfile/backends/_internalredirect.py
@@ -1,12 +1,8 @@
 import os.path
 
 from django.conf import settings
-from django.utils.encoding import smart_text, smart_bytes
-
-try:
-    from urllib.parse import quote
-except ImportError:
-    from urllib import quote
+from django.utils.encoding import force_bytes, force_text
+from django.utils.six.moves.urllib.parse import quote
 
 
 def _convert_file_to_url(filename):
@@ -20,5 +16,5 @@ def _convert_file_to_url(filename):
 
     # Python3 urllib.parse.quote accepts both unicode and bytes, while Python2 urllib.quote only accepts bytes.
     # So use bytes for quoting and then go back to unicode.
-    url = [smart_bytes(url_component) for url_component in url]
-    return smart_text(quote(b'/'.join(url)))
+    url = [force_bytes(url_component) for url_component in url]
+    return force_text(quote(b'/'.join(url)))
diff --git a/sendfile/backends/development.py b/sendfile/backends/development.py
index c717836..2c3822d 100644
--- a/sendfile/backends/development.py
+++ b/sendfile/backends/development.py
@@ -1,7 +1,7 @@
-from django.views.static import serve
-
 import os.path
 
+from django.views.static import serve
+
 
 def sendfile(request, filename, **kwargs):
     '''
diff --git a/sendfile/backends/mod_wsgi.py b/sendfile/backends/mod_wsgi.py
index 7fcd104..4e042a2 100644
--- a/sendfile/backends/mod_wsgi.py
+++ b/sendfile/backends/mod_wsgi.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import
-
 from django.http import HttpResponse
 
 from ._internalredirect import _convert_file_to_url
@@ -8,6 +6,9 @@
 def sendfile(request, filename, **kwargs):
     response = HttpResponse()
     response['Location'] = _convert_file_to_url(filename)
+    # Workaround for Django < 1.9
+    # https://docs.djangoproject.com/en/1.9/releases/1.9/#http-redirects-no-longer-forced-to-absolute-uris
+    #
     # need to destroy get_host() to stop django
     # rewriting our location to include http, so that
     # mod_wsgi is able to do the internal redirect
diff --git a/sendfile/backends/nginx.py b/sendfile/backends/nginx.py
index 29dc348..c62fe46 100644
--- a/sendfile/backends/nginx.py
+++ b/sendfile/backends/nginx.py
@@ -1,5 +1,3 @@
-from __future__ import absolute_import
-
 from django.http import HttpResponse
 
 from ._internalredirect import _convert_file_to_url
@@ -8,6 +6,6 @@
 def sendfile(request, filename, **kwargs):
     response = HttpResponse()
     url = _convert_file_to_url(filename)
-    response['X-Accel-Redirect'] = url.encode('utf-8')
+    response['X-Accel-Redirect'] = url
 
     return response
diff --git a/sendfile/backends/simple.py b/sendfile/backends/simple.py
index 9950151..da0aa54 100644
--- a/sendfile/backends/simple.py
+++ b/sendfile/backends/simple.py
@@ -1,10 +1,7 @@
 import os
-import stat
 import re
-try:
-    from email.utils import parsedate_tz, mktime_tz
-except ImportError:
-    from email.Utils import parsedate_tz, mktime_tz
+import stat
+from email.utils import mktime_tz, parsedate_tz
 
 from django.core.files.base import File
 from django.http import HttpResponse, HttpResponseNotModified
diff --git a/sendfile/backends/xsendfile.py b/sendfile/backends/xsendfile.py
index a87aa83..bc26cf4 100644
--- a/sendfile/backends/xsendfile.py
+++ b/sendfile/backends/xsendfile.py
@@ -3,6 +3,6 @@
 
 def sendfile(request, filename, **kwargs):
     response = HttpResponse()
-    response['X-Sendfile'] = unicode(filename).encode('utf-8')
+    response['X-Sendfile'] = filename
 
     return response
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..9ee696b
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,5 @@
+[bdist_wheel]
+universal = 1
+
+[flake8]
+ignore = E501
diff --git a/setup.py b/setup.py
index 406b127..75df3d7 100644
--- a/setup.py
+++ b/setup.py
@@ -1,10 +1,4 @@
-from distutils.core import setup
-
-try:
-    from distutils.command.build_py import build_py_2to3 as build_py
-except ImportError:
-    from distutils.command.build_py import build_py
-
+from setuptools import setup
 
 version = __import__('sendfile').__version__
 
@@ -18,30 +12,34 @@
     author_email='john@sensibledevelopment.com',
     url='https://github.com/johnsensible/django-sendfile',
     license='BSD',
-
-    requires=['Django (>=1.3)'],
-    install_requires=['Django>=1.3'],
-
+    install_requires=['Django>=1.8'],
     packages=['sendfile', 'sendfile.backends'],
     package_dir={
         'sendfile': 'sendfile',
         'sendfile.backends': 'sendfile/backends',
     },
-    package_data={
-        'sendfile': ['testfile.txt'],
-    },
-
     zip_safe=True,
     classifiers=[
-        'Development Status :: 4 - Beta',
+        'Development Status :: 5 - Production/Stable',
         'Environment :: Web Environment',
         'Framework :: Django',
+        'Framework :: Django :: 1.8',
+        'Framework :: Django :: 1.9',
+        'Framework :: Django :: 1.10',
+        'Framework :: Django :: 1.11',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: BSD License',
         'Operating System :: OS Independent',
         'Programming Language :: Python',
+        'Programming Language :: Python',
+        'Programming Language :: Python :: 2',
+        'Programming Language :: Python :: 2.7',
+        'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3.2',
+        'Programming Language :: Python :: 3.3',
+        'Programming Language :: Python :: 3.4',
+        'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
         'Topic :: Software Development :: Libraries :: Python Modules',
     ],
-
-    cmdclass={'build_py': build_py},
 )
diff --git a/sendfile/models.py b/tests/__init__.py
similarity index 100%
rename from sendfile/models.py
rename to tests/__init__.py
diff --git a/tests/settings.py b/tests/settings.py
new file mode 100644
index 0000000..4ba7f9d
--- /dev/null
+++ b/tests/settings.py
@@ -0,0 +1 @@
+SECRET_KEY = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890'
diff --git a/sendfile/tests.py b/tests/tests.py
similarity index 64%
rename from sendfile/tests.py
rename to tests/tests.py
index 0643cae..302f85c 100644
--- a/sendfile/tests.py
+++ b/tests/tests.py
@@ -1,18 +1,15 @@
 # coding=utf-8
-
-from django.conf import settings
-from django.test import TestCase
-from django.http import HttpResponse, Http404, HttpRequest
-from django.utils.encoding import smart_str
 import os.path
-from tempfile import mkdtemp
 import shutil
-from sendfile import sendfile as real_sendfile, _get_sendfile
+from tempfile import mkdtemp
+from unittest import TestCase
 
-try:
-    from urllib.parse import unquote
-except ImportError:
-    from urllib import unquote
+from django.http import Http404, HttpRequest, HttpResponse
+from django.test.utils import override_settings
+from django.utils.six.moves.urllib.parse import unquote
+
+from sendfile import sendfile as real_sendfile
+from sendfile import _get_sendfile
 
 
 def sendfile(request, filename, **kwargs):
@@ -26,11 +23,7 @@ class TempFileTestCase(TestCase):
     def setUp(self):
         super(TempFileTestCase, self).setUp()
         self.TEMP_FILE_ROOT = mkdtemp()
-
-    def tearDown(self):
-        super(TempFileTestCase, self).tearDown()
-        if os.path.exists(self.TEMP_FILE_ROOT):
-            shutil.rmtree(self.TEMP_FILE_ROOT)
+        self.addCleanup(shutil.rmtree, self.TEMP_FILE_ROOT)
 
     def ensure_file(self, filename):
         path = os.path.join(self.TEMP_FILE_ROOT, filename)
@@ -44,52 +37,52 @@ class TestSendfile(TempFileTestCase):
     def setUp(self):
         super(TestSendfile, self).setUp()
         # set ourselves to be the sendfile backend
-        settings.SENDFILE_BACKEND = 'sendfile.tests'
+        cm = override_settings(SENDFILE_BACKEND='tests.tests')
+        cm.enable()
+        self.addCleanup(cm.disable)
         _get_sendfile.clear()
 
     def _get_readme(self):
         return self.ensure_file('testfile.txt')
 
     def test_404(self):
-        try:
+        with self.assertRaises(Http404):
             real_sendfile(HttpRequest(), 'fhdsjfhjk.txt')
-        except Http404:
-            pass
 
     def test_sendfile(self):
         response = real_sendfile(HttpRequest(), self._get_readme())
-        self.assertTrue(response is not None)
+        self.assertIsNotNone(response)
         self.assertEqual('text/plain', response['Content-Type'])
-        self.assertEqual(self._get_readme(), smart_str(response.content))
+        self.assertEqual(self._get_readme(), response.content.decode(response.charset))
 
     def test_set_mimetype(self):
         response = real_sendfile(HttpRequest(), self._get_readme(), mimetype='text/plain')
-        self.assertTrue(response is not None)
+        self.assertIsNotNone(response)
         self.assertEqual('text/plain', response['Content-Type'])
 
     def test_set_encoding(self):
         response = real_sendfile(HttpRequest(), self._get_readme(), encoding='utf8')
-        self.assertTrue(response is not None)
+        self.assertIsNotNone(response)
         self.assertEqual('utf8', response['Content-Encoding'])
 
     def test_attachment(self):
         response = real_sendfile(HttpRequest(), self._get_readme(), attachment=True)
-        self.assertTrue(response is not None)
+        self.assertIsNotNone(response)
         self.assertEqual('attachment; filename="testfile.txt"', response['Content-Disposition'])
 
     def test_attachment_filename_false(self):
         response = real_sendfile(HttpRequest(), self._get_readme(), attachment=True, attachment_filename=False)
-        self.assertTrue(response is not None)
+        self.assertIsNotNone(response)
         self.assertEqual('attachment', response['Content-Disposition'])
 
     def test_attachment_filename(self):
         response = real_sendfile(HttpRequest(), self._get_readme(), attachment=True, attachment_filename='tests.txt')
-        self.assertTrue(response is not None)
+        self.assertIsNotNone(response)
         self.assertEqual('attachment; filename="tests.txt"', response['Content-Disposition'])
 
     def test_attachment_filename_unicode(self):
         response = real_sendfile(HttpRequest(), self._get_readme(), attachment=True, attachment_filename='test’s.txt')
-        self.assertTrue(response is not None)
+        self.assertIsNotNone(response)
         self.assertEqual('attachment; filename="tests.txt"; filename*=UTF-8\'\'test%E2%80%99s.txt', response['Content-Disposition'])
 
 
@@ -97,61 +90,69 @@ class TestXSendfileBackend(TempFileTestCase):
 
     def setUp(self):
         super(TestXSendfileBackend, self).setUp()
-        settings.SENDFILE_BACKEND = 'sendfile.backends.xsendfile'
+        cm = override_settings(SENDFILE_BACKEND='sendfile.backends.xsendfile')
+        cm.enable()
+        self.addCleanup(cm.disable)
         _get_sendfile.clear()
 
     def test_correct_file_in_xsendfile_header(self):
         filepath = self.ensure_file('readme.txt')
         response = real_sendfile(HttpRequest(), filepath)
-        self.assertTrue(response is not None)
+        self.assertIsNotNone(response)
         self.assertEqual(filepath, response['X-Sendfile'])
 
     def test_xsendfile_header_containing_unicode(self):
-        filepath = self.ensure_file(u'péter_là_gueule.txt')
+        filepath = self.ensure_file('péter_là_gueule.txt')
         response = real_sendfile(HttpRequest(), filepath)
-        self.assertTrue(response is not None)
-        self.assertEqual(smart_str(filepath), response['X-Sendfile'])
+        self.assertIsNotNone(response)
+        self.assertEqual(filepath, response['X-Sendfile'])
 
 
 class TestNginxBackend(TempFileTestCase):
 
     def setUp(self):
         super(TestNginxBackend, self).setUp()
-        settings.SENDFILE_BACKEND = 'sendfile.backends.nginx'
-        settings.SENDFILE_ROOT = self.TEMP_FILE_ROOT
-        settings.SENDFILE_URL = '/private'
+        cm = override_settings(
+            SENDFILE_BACKEND='sendfile.backends.nginx',
+            SENDFILE_ROOT=self.TEMP_FILE_ROOT,
+            SENDFILE_URL='/private')
+        cm.enable()
+        self.addCleanup(cm.disable)
         _get_sendfile.clear()
 
     def test_correct_url_in_xaccelredirect_header(self):
         filepath = self.ensure_file('readme.txt')
         response = real_sendfile(HttpRequest(), filepath)
-        self.assertTrue(response is not None)
+        self.assertIsNotNone(response)
         self.assertEqual('/private/readme.txt', response['X-Accel-Redirect'])
 
     def test_xaccelredirect_header_containing_unicode(self):
-        filepath = self.ensure_file(u'péter_là_gueule.txt')
+        filepath = self.ensure_file('péter_là_gueule.txt')
         response = real_sendfile(HttpRequest(), filepath)
-        self.assertTrue(response is not None)
-        self.assertEqual(u'/private/péter_là_gueule.txt'.encode('utf-8'), unquote(response['X-Accel-Redirect']))
+        self.assertIsNotNone(response)
+        self.assertEqual('/private/péter_là_gueule.txt', unquote(response['X-Accel-Redirect']))
 
 
 class TestModWsgiBackend(TempFileTestCase):
 
     def setUp(self):
         super(TestModWsgiBackend, self).setUp()
-        settings.SENDFILE_BACKEND = 'sendfile.backends.mod_wsgi'
-        settings.SENDFILE_ROOT = self.TEMP_FILE_ROOT
-        settings.SENDFILE_URL = '/private'
+        cm = override_settings(
+            SENDFILE_BACKEND='sendfile.backends.mod_wsgi',
+            SENDFILE_ROOT=self.TEMP_FILE_ROOT,
+            SENDFILE_URL='/private')
+        cm.enable()
+        self.addCleanup(cm.disable)
         _get_sendfile.clear()
 
     def test_correct_url_in_location_header(self):
         filepath = self.ensure_file('readme.txt')
         response = real_sendfile(HttpRequest(), filepath)
-        self.assertTrue(response is not None)
+        self.assertIsNotNone(response)
         self.assertEqual('/private/readme.txt', response['Location'])
 
     def test_location_header_containing_unicode(self):
-        filepath = self.ensure_file(u'péter_là_gueule.txt')
+        filepath = self.ensure_file('péter_là_gueule.txt')
         response = real_sendfile(HttpRequest(), filepath)
-        self.assertTrue(response is not None)
-        self.assertEqual(u'/private/péter_là_gueule.txt'.encode('utf-8'), unquote(response['Location']))
+        self.assertIsNotNone(response)
+        self.assertEqual('/private/péter_là_gueule.txt', unquote(response['Location']))