diff --git a/.travis.yml b/.travis.yml
index f447312..c3c57cf 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,7 @@
 language: python
 env:
   - TOXENV=py27
+  - TOXENV=py33
   - TOXENV=flake8
   - TOXENV=sphinx
   - TOXENV=readme
diff --git a/CHANGELOG b/CHANGELOG
index 89f37c9..9a74610 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -8,6 +8,8 @@ future releases, check `milestones`_ and :doc:`/about/vision`.
 1.6 (unreleased)
 ----------------
 
+- Feature #46: introduced support for Python>=3.3.
+
 - Feature #74: the Makefile in project's repository no longer creates a
   virtualenv. Developers setup the environment as they like, i.e. using
   virtualenv, virtualenvwrapper or whatever. Tests are run with tox.
diff --git a/demo/demoproject/virtual/views.py b/demo/demoproject/virtual/views.py
index 8bb7020..805651f 100644
--- a/demo/demoproject/virtual/views.py
+++ b/demo/demoproject/virtual/views.py
@@ -1,4 +1,4 @@
-from StringIO import StringIO
+from six import StringIO
 
 from django.core.files.base import ContentFile
 
@@ -10,7 +10,7 @@ from django_downloadview import StringIteratorIO
 class TextDownloadView(VirtualDownloadView):
     def get_file(self):
         """Return :class:`django.core.files.base.ContentFile` object."""
-        return ContentFile(u"Hello world!\n", name='hello-world.txt')
+        return ContentFile(b"Hello world!\n", name='hello-world.txt')
 
 
 class StringIODownloadView(VirtualDownloadView):
diff --git a/django_downloadview/apache/tests.py b/django_downloadview/apache/tests.py
index b0ac5db..0aa17b0 100644
--- a/django_downloadview/apache/tests.py
+++ b/django_downloadview/apache/tests.py
@@ -1,3 +1,4 @@
+from six import iteritems
 from django_downloadview.apache.response import XSendfileResponse
 
 
@@ -21,7 +22,7 @@ class XSendfileValidator(object):
 
         """
         self.assert_x_sendfile_response(test_case, response)
-        for key, value in assertions.iteritems():
+        for key, value in iteritems(assertions):
             assert_func = getattr(self, 'assert_%s' % key)
             assert_func(test_case, response, value)
 
diff --git a/django_downloadview/files.py b/django_downloadview/files.py
index 41ebb6b..e41534d 100644
--- a/django_downloadview/files.py
+++ b/django_downloadview/files.py
@@ -2,7 +2,7 @@
 """File wrappers for use as exchange data between views and responses."""
 from __future__ import absolute_import
 from io import BytesIO
-from urlparse import urlparse
+from six.moves.urllib.parse import urlparse
 
 from django.core.files.base import File
 from django.utils.encoding import force_bytes
diff --git a/django_downloadview/nginx/tests.py b/django_downloadview/nginx/tests.py
index 0cf7349..02bfec9 100644
--- a/django_downloadview/nginx/tests.py
+++ b/django_downloadview/nginx/tests.py
@@ -1,3 +1,4 @@
+from six import iteritems
 from django_downloadview.nginx.response import XAccelRedirectResponse
 
 
@@ -35,7 +36,7 @@ class XAccelRedirectValidator(object):
 
         """
         self.assert_x_accel_redirect_response(test_case, response)
-        for key, value in assertions.iteritems():
+        for key, value in iteritems(assertions):
             assert_func = getattr(self, 'assert_%s' % key)
             assert_func(test_case, response, value)
 
diff --git a/django_downloadview/response.py b/django_downloadview/response.py
index 9cb7de7..c22775f 100644
--- a/django_downloadview/response.py
+++ b/django_downloadview/response.py
@@ -4,7 +4,8 @@ import os
 import mimetypes
 import re
 import unicodedata
-import urllib
+import six
+from six.moves import urllib
 
 from django.conf import settings
 from django.http import HttpResponse, StreamingHttpResponse
@@ -12,30 +13,27 @@ from django.utils.encoding import force_str
 
 
 def encode_basename_ascii(value):
-    """Return US-ASCII encoded ``value`` for use in Content-Disposition header.
+    u"""Return US-ASCII encoded ``value`` for Content-Disposition header.
 
-    >>> encode_basename_ascii(unicode('éà', 'utf-8'))
-    u'ea'
+    >>> print(encode_basename_ascii(u'éà'))
+    ea
 
     Spaces are converted to underscores.
 
-    >>> encode_basename_ascii(' ')
-    u'_'
-
-    Text with non US-ASCII characters is expected to be unicode.
-
-    >>> encode_basename_ascii('éà')  # doctest: +ELLIPSIS
-    Traceback (most recent call last):
-        ...
-    UnicodeDecodeError: \'ascii\' codec can\'t decode byte ...
+    >>> print(encode_basename_ascii(' '))
+    _
 
     Of course, ASCII values are not modified.
 
-    >>> encode_basename_ascii('ea')
-    u'ea'
+    >>> print(encode_basename_ascii('ea'))
+    ea
+    >>> print(encode_basename_ascii(b'ea'))
+    ea
 
     """
-    ascii_basename = unicode(value)
+    if isinstance(value, six.binary_type):
+        value = value.decode('utf-8')
+    ascii_basename = six.text_type(value)
     ascii_basename = unicodedata.normalize('NFKD', ascii_basename)
     ascii_basename = ascii_basename.encode('ascii', 'ignore')
     ascii_basename = ascii_basename.decode('ascii')
@@ -44,34 +42,34 @@ def encode_basename_ascii(value):
 
 
 def encode_basename_utf8(value):
-    """Return UTF-8 encoded ``value`` for use in Content-Disposition header.
+    u"""Return UTF-8 encoded ``value`` for use in Content-Disposition header.
 
-    >>> encode_basename_utf8(u' .txt')
-    '%20.txt'
+    >>> print(encode_basename_utf8(u' .txt'))
+    %20.txt
 
-    >>> encode_basename_utf8(unicode('éà', 'utf-8'))
-    '%C3%A9%C3%A0'
+    >>> print(encode_basename_utf8(u'éà'))
+    %C3%A9%C3%A0
 
     """
-    return urllib.quote(force_str(value))
+    return urllib.parse.quote(force_str(value))
 
 
 def content_disposition(filename):
-    """Return value of ``Content-Disposition`` header with 'attachment'.
+    u"""Return value of ``Content-Disposition`` header with 'attachment'.
 
-    >>> content_disposition('demo.txt')
-    'attachment; filename=demo.txt'
+    >>> print(content_disposition('demo.txt'))
+    attachment; filename=demo.txt
 
     If filename is empty, only "attachment" is returned.
 
-    >>> content_disposition('')
-    'attachment'
+    >>> print(content_disposition(''))
+    attachment
 
     If filename contains non US-ASCII characters, the returned value contains
     UTF-8 encoded filename and US-ASCII fallback.
 
-    >>> content_disposition(unicode('é.txt', 'utf-8'))
-    "attachment; filename=e.txt; filename*=UTF-8''%C3%A9.txt"
+    >>> print(content_disposition(u'é.txt'))
+    attachment; filename=e.txt; filename*=UTF-8''%C3%A9.txt
 
     """
     if not filename:
diff --git a/django_downloadview/test.py b/django_downloadview/test.py
index e9fc454..714e8c2 100644
--- a/django_downloadview/test.py
+++ b/django_downloadview/test.py
@@ -1,5 +1,6 @@
 """Testing utilities."""
 import shutil
+from six import iteritems
 import tempfile
 
 from django.conf import settings
@@ -101,7 +102,7 @@ class DownloadResponseValidator(object):
 
         """
         self.assert_download_response(test_case, response)
-        for key, value in assertions.iteritems():
+        for key, value in iteritems(assertions):
             assert_func = getattr(self, 'assert_%s' % key)
             assert_func(test_case, response, value)
 
@@ -138,7 +139,9 @@ class DownloadResponseValidator(object):
         test_case.assertTrue(response['Content-Type'].startswith(value))
 
     def assert_content(self, test_case, response, value):
-        test_case.assertEqual(''.join(response.streaming_content), value)
+        test_case.assertEqual(
+            ''.join([s.decode('utf-8') for s in response.streaming_content]),
+            value)
 
     def assert_attachment(self, test_case, response, value):
         test_case.assertEqual('attachment;' in response['Content-Disposition'],
diff --git a/django_downloadview/tests/api.py b/django_downloadview/tests/api.py
index 4113043..ce2ebfc 100644
--- a/django_downloadview/tests/api.py
+++ b/django_downloadview/tests/api.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 """Test suite around :mod:`django_downloadview.api` and deprecation plan."""
 import unittest
+from six.moves import reload_module as reload
 import warnings
 
 from django.core.exceptions import ImproperlyConfigured
diff --git a/django_downloadview/utils.py b/django_downloadview/utils.py
index f5b3326..b1facc1 100644
--- a/django_downloadview/utils.py
+++ b/django_downloadview/utils.py
@@ -26,8 +26,8 @@ def url_basename(url, content_type):
 
     If URL contains extension, it is kept as-is.
 
-    >>> url_basename(u'/path/to/somefile.rst', 'text/plain')
-    u'somefile.rst'
+    >>> print(url_basename(u'/path/to/somefile.rst', 'text/plain'))
+    somefile.rst
 
     """
     return url.split('/')[-1]
@@ -43,5 +43,5 @@ def import_member(import_string):
 
     """
     module_name, factory_name = str(import_string).rsplit('.', 1)
-    module = __import__(module_name, globals(), locals(), [factory_name], -1)
+    module = __import__(module_name, globals(), locals(), [factory_name], 0)
     return getattr(module, factory_name)
diff --git a/setup.py b/setup.py
index 12809e6..d6f037b 100644
--- a/setup.py
+++ b/setup.py
@@ -35,7 +35,7 @@ KEYWORDS = ['file',
             'mod_xsendfile',
             'offload']
 PACKAGES = [NAME.replace('-', '_')]
-REQUIREMENTS = ['setuptools', 'Django>=1.5', 'requests']
+REQUIREMENTS = ['setuptools', 'Django>=1.5', 'requests', 'six']
 if IS_PYTHON2:
     REQUIREMENTS.append('mock')
 ENTRY_POINTS = {}
diff --git a/tests/packaging.py b/tests/packaging.py
index 97b673e..7a97105 100644
--- a/tests/packaging.py
+++ b/tests/packaging.py
@@ -50,44 +50,3 @@ class VersionTestCase(unittest.TestCase):
                          'You may need to run ``make develop`` to update the '
                          'installed version in development environment.'
                          % (self.get_version(), file_version))
-
-
-class ReadMeTestCase(unittest.TestCase):
-    """Test suite around README file."""
-    def test_readme_build(self):
-        """README builds to HTML without errors."""
-        # Run build.
-        import docutils.core
-        import docutils.io
-        source = open(os.path.join(project_dir, 'README.rst')).read()
-        writer_name = 'html'
-        import sys
-        from StringIO import StringIO
-        stderr_backup = sys.stderr
-        sys.stderr = StringIO()
-        output, pub = docutils.core.publish_programmatically(
-            source=source,
-            source_class=docutils.io.StringInput,
-            source_path=None,
-            destination_class=docutils.io.StringOutput,
-            destination=None,
-            destination_path=None,
-            reader=None,
-            reader_name='standalone',
-            parser=None,
-            parser_name='restructuredtext',
-            writer=None,
-            writer_name=writer_name,
-            settings=None,
-            settings_spec=None,
-            settings_overrides=None,
-            config_section=None,
-            enable_exit_status=False)
-        sys.stderr = stderr_backup
-        errors = pub._stderr.stream.getvalue()
-        # Check result.
-        self.assertFalse(errors, "Docutils reported errors while building "
-                                 "readme content from reStructuredText to "
-                                 "HTML. So PyPI would display the readme as "
-                                 "text instead of HTML. Errors are:\n%s"
-                                 % errors)
diff --git a/tox.ini b/tox.ini
index 266a4d5..e64f108 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,flake8,sphinx,readme
+envlist = py27,py33,flake8,sphinx,readme
 
 [testenv]
 deps =
@@ -39,6 +39,6 @@ deps =
     pygments
 commands =
     mkdir -p var/docs
-	rst2html.py --exit-status=2 README.rst var/docs/README.html
+    rst2html.py --exit-status=2 README.rst var/docs/README.html
 whitelist_externals =
     mkdir