diff --git a/.travis.yml b/.travis.yml
index 666437d..3231fc3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,7 @@
 language: python
-python: "2.7"
+python:
+    - "2.7"
+    - "3.3"
 env:
     global:
         - IS_TRAVIS=true
diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index 74e7b4d..2d10f7c 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -3,8 +3,8 @@
   * Make sure you have the latest version by executing ``pip install --user
     --upgrade vdirsyncer``.
 
-  * Include your configuration, the commands you're executing, and their
-    output.
+  * Include the Python version, your configuration, the commands you're
+    executing, and their output.
 
   * Use ``--verbosity=DEBUG`` when including output from vdirsyncer.
 
diff --git a/README.rst b/README.rst
index 1548bbf..48e8898 100644
--- a/README.rst
+++ b/README.rst
@@ -34,9 +34,11 @@ informations on problems with ownCloud.
 How to use
 ==========
 
+vdirsyncer requires Python >= 2.7 or Python >= 3.3.
+
 As all Python packages, vdirsyncer can be installed with ``pip``::
 
-    pip install --user vdirsyncer  # use the pip for Python 2
+    pip install --user vdirsyncer
 
 Then copy ``example.cfg`` to ``~/.vdirsyncer/config`` and edit it. You can use the
 `VDIRSYNCER_CONFIG` environment variable to change the path vdirsyncer will
diff --git a/tests/storage/__init__.py b/tests/storage/__init__.py
index a774529..b19ba85 100644
--- a/tests/storage/__init__.py
+++ b/tests/storage/__init__.py
@@ -9,6 +9,7 @@
 
 from vdirsyncer.storage.base import Item
 import vdirsyncer.exceptions as exceptions
+from vdirsyncer.utils import text_type
 from .. import assert_item_equals
 import random
 import pytest
@@ -33,7 +34,7 @@ class StorageTests(object):
     def test_generic(self):
         items = map(self._create_bogus_item, range(1, 10))
         for i, item in enumerate(items):
-            assert item.uid == unicode(i + 1), item.raw
+            assert item.uid == text_type(i + 1), item.raw
         s = self._get_storage()
         hrefs = []
         for item in items:
diff --git a/tests/storage/dav/servers/radicale/__init__.py b/tests/storage/dav/servers/radicale/__init__.py
index 1faf706..3b1c33f 100644
--- a/tests/storage/dav/servers/radicale/__init__.py
+++ b/tests/storage/dav/servers/radicale/__init__.py
@@ -2,8 +2,8 @@
 
 import sys
 import os
-import urlparse
 import pytest
+from vdirsyncer.utils import urlparse
 
 from werkzeug.test import Client
 from werkzeug.wrappers import BaseResponse as WerkzeugResponse
diff --git a/tests/storage/test_filesystem.py b/tests/storage/test_filesystem.py
index b2faf5f..401d391 100644
--- a/tests/storage/test_filesystem.py
+++ b/tests/storage/test_filesystem.py
@@ -46,8 +46,8 @@ class TestFilesystemStorage(StorageTests):
         s = self.storage_class(str(tmpdir), '.txt')
 
         class BrokenItem(object):
-            raw = b'Ц, Ш, Л, ж, Д, З, Ю'
+            raw = u'Ц, Ш, Л, ж, Д, З, Ю'.encode('utf-8')
             uid = 'jeezus'
-        with pytest.raises(UnicodeError):
+        with pytest.raises(TypeError):
             s.upload(BrokenItem)
         assert not tmpdir.listdir()
diff --git a/tests/storage/test_http.py b/tests/storage/test_http.py
index d874503..95c806f 100644
--- a/tests/storage/test_http.py
+++ b/tests/storage/test_http.py
@@ -18,29 +18,25 @@ class TestHttpStorage(object):
         collection_url = 'http://127.0.0.1/calendar/collection.ics'
 
         items = [
-            dedent(b'''
-                    BEGIN:VEVENT
-                    SUMMARY:Eine Kurzinfo
-                    DESCRIPTION:Beschreibung des Termines
-                    END:VEVENT
-                   ''').strip(),
-            dedent(b'''
-                    BEGIN:VEVENT
-                    SUMMARY:Eine zweite Kurzinfo
-                    DESCRIPTION:Beschreibung des anderen Termines
-                    BEGIN:VALARM
-                    ACTION:AUDIO
-                    TRIGGER:19980403T120000
-                    ATTACH;FMTTYPE=audio/basic:http://host.com/pub/ssbanner.aud
-                    REPEAT:4
-                    DURATION:PT1H
-                    END:VALARM
-                    END:VEVENT
-                   ''').strip()
+            (u'BEGIN:VEVENT\n'
+             u'SUMMARY:Eine Kurzinfo\n'
+             u'DESCRIPTION:Beschreibung des Termines\n'
+             u'END:VEVENT'),
+            (u'BEGIN:VEVENT\n'
+             u'SUMMARY:Eine zweite Kurzinfo\n'
+             u'DESCRIPTION:Beschreibung des anderen Termines\n'
+             u'BEGIN:VALARM\n'
+             u'ACTION:AUDIO\n'
+             u'TRIGGER:19980403T120000\n'
+             u'ATTACH;FMTTYPE=audio/basic:http://host.com/pub/ssbanner.aud\n'
+             u'REPEAT:4\n'
+             u'DURATION:PT1H\n'
+             u'END:VALARM\n'
+             u'END:VEVENT')
         ]
 
         responses = [
-            '\n'.join([b'BEGIN:VCALENDAR'] + items + [b'END:VCALENDAR'])
+            u'\n'.join([u'BEGIN:VCALENDAR'] + items + [u'END:VCALENDAR'])
         ] * 2
 
         def get(method, url, *a, **kw):
@@ -49,7 +45,8 @@ class TestHttpStorage(object):
             r = Response()
             r.status_code = 200
             assert responses
-            r._content = responses.pop()
+            r._content = responses.pop().encode('utf-8')
+            r.encoding = 'utf-8'
             return r
 
         monkeypatch.setattr('requests.request', get)
diff --git a/vdirsyncer/cli.py b/vdirsyncer/cli.py
index 48748bd..29b61b5 100644
--- a/vdirsyncer/cli.py
+++ b/vdirsyncer/cli.py
@@ -10,7 +10,6 @@
 import os
 import sys
 import json
-import ConfigParser
 from vdirsyncer.sync import sync
 from vdirsyncer.utils import expand_path, split_dict, parse_options
 from vdirsyncer.storage import storage_names
@@ -18,11 +17,17 @@ import vdirsyncer.log as log
 import argvard
 
 
+try:
+    from ConfigParser import RawConfigParser
+except ImportError:
+    from configparser import RawConfigParser
+
+
 cli_logger = log.get('cli')
 
 
 def load_config(fname, pair_options=('collections', 'conflict_resolution')):
-    c = ConfigParser.RawConfigParser()
+    c = RawConfigParser()
     c.read(fname)
 
     get_options = lambda s: dict(parse_options(c.items(s)))
diff --git a/vdirsyncer/storage/base.py b/vdirsyncer/storage/base.py
index 32701ab..028a3e4 100644
--- a/vdirsyncer/storage/base.py
+++ b/vdirsyncer/storage/base.py
@@ -8,6 +8,7 @@
 '''
 
 from .. import exceptions
+from .. import utils
 
 
 class Item(object):
@@ -15,7 +16,7 @@ class Item(object):
     '''should-be-immutable wrapper class for VCALENDAR and VCARD'''
 
     def __init__(self, raw):
-        assert type(raw) is unicode
+        assert isinstance(raw, utils.text_type)
         raw = raw.splitlines()
         self.uid = None
 
diff --git a/vdirsyncer/storage/dav.py b/vdirsyncer/storage/dav.py
index 4e1c9da..e00b61e 100644
--- a/vdirsyncer/storage/dav.py
+++ b/vdirsyncer/storage/dav.py
@@ -11,10 +11,9 @@ from .base import Storage, Item
 from .http import prepare_auth, prepare_verify, USERAGENT
 from .. import exceptions
 from .. import log
-from ..utils import request, get_password
+from ..utils import request, get_password, urlparse
 import requests
 import datetime
-import urlparse
 from lxml import etree
 
 
@@ -166,7 +165,7 @@ class DavStorage(Storage):
         hrefs_left = set(hrefs)
         for element in root.iter('{DAV:}response'):
             href = self._normalize_href(
-                element.find('{DAV:}href').text.decode(response.encoding))
+                element.find('{DAV:}href').text)
             raw = element \
                 .find('{DAV:}propstat') \
                 .find('{DAV:}prop') \
diff --git a/vdirsyncer/storage/filesystem.py b/vdirsyncer/storage/filesystem.py
index b98efce..066f32b 100644
--- a/vdirsyncer/storage/filesystem.py
+++ b/vdirsyncer/storage/filesystem.py
@@ -10,7 +10,7 @@
 import os
 from vdirsyncer.storage.base import Storage, Item
 import vdirsyncer.exceptions as exceptions
-from vdirsyncer.utils import expand_path
+from vdirsyncer.utils import expand_path, text_type
 import vdirsyncer.log as log
 logger = log.get('storage.filesystem')
 
@@ -76,7 +76,7 @@ class FilesystemStorage(Storage):
             if os.path.exists(path):
                 raise IOError('{} is not a directory.')
             if create:
-                os.makedirs(path, 0750)
+                os.makedirs(path, 0o750)
             else:
                 raise IOError('Directory {} does not exist. Use create = '
                               'True in your configuration to automatically '
@@ -125,6 +125,10 @@ class FilesystemStorage(Storage):
         fpath = self._get_filepath(href)
         if os.path.exists(fpath):
             raise exceptions.AlreadyExistingError(item.uid)
+
+        if not isinstance(item.raw, text_type):
+            raise TypeError('item.raw must be a unicode string.')
+
         with safe_write(fpath, 'wb+') as f:
             f.write(item.raw.encode(self.encoding))
             return href, f.get_etag()
@@ -140,6 +144,9 @@ class FilesystemStorage(Storage):
         if etag != actual_etag:
             raise exceptions.WrongEtagError(etag, actual_etag)
 
+        if not isinstance(item.raw, text_type):
+            raise TypeError('item.raw must be a unicode string.')
+
         with safe_write(fpath, 'wb') as f:
             f.write(item.raw.encode(self.encoding))
             return f.get_etag()
diff --git a/vdirsyncer/storage/http.py b/vdirsyncer/storage/http.py
index 847e6f3..edb158f 100644
--- a/vdirsyncer/storage/http.py
+++ b/vdirsyncer/storage/http.py
@@ -1,4 +1,3 @@
-
 # -*- coding: utf-8 -*-
 '''
     vdirsyncer.storage.http
@@ -8,10 +7,10 @@
     :license: MIT, see LICENSE for more details.
 '''
 
-import urlparse
 import hashlib
 from .base import Storage, Item
-from vdirsyncer.utils import expand_path, get_password, request
+from vdirsyncer.utils import expand_path, get_password, request, urlparse, \
+     text_type
 
 USERAGENT = 'vdirsyncer'
 
@@ -59,7 +58,7 @@ def prepare_auth(auth, username, password):
 
 
 def prepare_verify(verify):
-    if isinstance(verify, (str, unicode)):
+    if isinstance(verify, (text_type, bytes)):
         return expand_path(verify)
     return verify
 
@@ -110,8 +109,8 @@ class HttpStorage(Storage):
             self._items[uid] = item
 
         for uid, item in self._items.items():
-            yield uid, hashlib.sha256(item.raw).hexdigest()
+            yield uid, hashlib.sha256(item.raw.encode('utf-8')).hexdigest()
 
     def get(self, href):
         x = self._items[href]
-        return x, hashlib.sha256(x.raw).hexdigest()
+        return x, hashlib.sha256(x.raw.encode('utf-8')).hexdigest()
diff --git a/vdirsyncer/sync.py b/vdirsyncer/sync.py
index 96a0fe9..ae836fe 100644
--- a/vdirsyncer/sync.py
+++ b/vdirsyncer/sync.py
@@ -19,6 +19,7 @@ import itertools
 
 import vdirsyncer.exceptions as exceptions
 import vdirsyncer.log
+from .utils import iteritems, itervalues
 sync_logger = vdirsyncer.log.get('sync')
 
 
@@ -58,18 +59,18 @@ def sync(storage_a, storage_b, status, conflict_resolution=None):
     '''
     a_href_to_status = dict(
         (href_a, (uid, etag_a))
-        for uid, (href_a, etag_a, href_b, etag_b) in status.iteritems()
+        for uid, (href_a, etag_a, href_b, etag_b) in iteritems(status)
     )
     b_href_to_status = dict(
         (href_b, (uid, etag_b))
-        for uid, (href_a, etag_a, href_b, etag_b) in status.iteritems()
+        for uid, (href_a, etag_a, href_b, etag_b) in iteritems(status)
     )
     # href => {'etag': etag, 'item': optional item, 'uid': uid}
     list_a = dict(prepare_list(storage_a, a_href_to_status))
     list_b = dict(prepare_list(storage_b, b_href_to_status))
 
-    a_uid_to_href = dict((x['uid'], href) for href, x in list_a.iteritems())
-    b_uid_to_href = dict((x['uid'], href) for href, x in list_b.iteritems())
+    a_uid_to_href = dict((x['uid'], href) for href, x in iteritems(list_a))
+    b_uid_to_href = dict((x['uid'], href) for href, x in iteritems(list_b))
     del a_href_to_status, b_href_to_status
 
     storages = {
@@ -175,8 +176,8 @@ def get_actions(storages, status):
     storage_a, list_a, a_uid_to_href = storages['a']
     storage_b, list_b, b_uid_to_href = storages['b']
 
-    uids_a = (x['uid'] for x in list_a.itervalues())
-    uids_b = (x['uid'] for x in list_b.itervalues())
+    uids_a = (x['uid'] for x in itervalues(list_a))
+    uids_b = (x['uid'] for x in itervalues(list_b))
     handled = set()
     for uid in itertools.chain(uids_a, uids_b, status):
         if uid in handled:
diff --git a/vdirsyncer/utils.py b/vdirsyncer/utils.py
index 4aafd4a..7365135 100644
--- a/vdirsyncer/utils.py
+++ b/vdirsyncer/utils.py
@@ -8,13 +8,24 @@
 '''
 
 import os
+import sys
 import vdirsyncer.log
+import requests
 
 
-try:  # pragma: no cover
-    import urllib.parse as urlparse
-except ImportError:  # pragma: no cover
+PY2 = sys.version_info[0] == 2
+
+
+if PY2:
     import urlparse
+    text_type = unicode
+    iteritems = lambda x: x.iteritems()
+    itervalues = lambda x: x.itervalues()
+else:
+    import urllib.parse as urlparse
+    text_type = str
+    iteritems = lambda x: x.items()
+    itervalues = lambda x: x.values()
 
 
 try:
@@ -23,9 +34,6 @@ except ImportError:
     keyring = None
 
 
-import requests
-
-
 password_key_prefix = 'vdirsyncer:'