diff --git a/setup.py b/setup.py
index 12a6671b3..915c8997f 100644
--- a/setup.py
+++ b/setup.py
@@ -17,6 +17,8 @@
 
 install_requires = []
 
+install_requires.append('six')
+
 if sys.version_info < (2, 6):
     warnings.warn(
         'Python 2.5 is no longer officially supported by Stripe. '
@@ -61,7 +63,6 @@
     install_requires=install_requires,
     test_suite='stripe.test.all',
     tests_require=['unittest2', 'mock'],
-    use_2to3=True,
     classifiers=[
         "Development Status :: 5 - Production/Stable",
         "Intended Audience :: Developers",
diff --git a/stripe/api_requestor.py b/stripe/api_requestor.py
index 0caac71f1..0ce36bf31 100644
--- a/stripe/api_requestor.py
+++ b/stripe/api_requestor.py
@@ -2,10 +2,11 @@
 import datetime
 import platform
 import time
-import urllib
-import urlparse
 import warnings
 
+import six
+from six.moves.urllib.parse import urlencode, urlsplit, urlunsplit
+
 import stripe
 from stripe import error, oauth_error, http_client, version, util
 from stripe.multipart_data_generator import MultipartDataGenerator
@@ -22,13 +23,13 @@ def _encode_datetime(dttime):
 
 def _encode_nested_dict(key, data, fmt='%s[%s]'):
     d = {}
-    for subkey, subvalue in data.iteritems():
+    for subkey, subvalue in six.iteritems(data):
         d[fmt % (key, subkey)] = subvalue
     return d
 
 
 def _api_encode(data):
-    for key, value in data.iteritems():
+    for key, value in six.iteritems(data):
         key = util.utf8(key)
         if value is None:
             continue
@@ -53,12 +54,12 @@ def _api_encode(data):
 
 
 def _build_api_url(url, query):
-    scheme, netloc, path, base_query, fragment = urlparse.urlsplit(url)
+    scheme, netloc, path, base_query, fragment = urlsplit(url)
 
     if base_query:
         query = '%s&%s' % (base_query, query)
 
-    return urlparse.urlunsplit((scheme, netloc, path, query, fragment))
+    return urlunsplit((scheme, netloc, path, query, fragment))
 
 
 class APIRequestor(object):
@@ -124,7 +125,7 @@ def encode(cls, d):
             'If you need public access to this function, please email us '
             'at support@stripe.com.',
             DeprecationWarning)
-        return urllib.urlencode(list(_api_encode(d)))
+        return urlencode(list(_api_encode(d)))
 
     @classmethod
     def build_url(cls, url, params):
@@ -165,7 +166,7 @@ def handle_error_response(self, rbody, rcode, resp, rheaders):
         # OAuth errors are a JSON object where `error` is a string. In
         # contrast, in API errors, `error` is a hash with sub-keys. We use
         # this property to distinguish between OAuth and API errors.
-        if isinstance(error_data, basestring):
+        if isinstance(error_data, six.string_types):
             err = self.specific_oauth_error(
                 rbody, rcode, resp, rheaders, error_data)
 
@@ -300,7 +301,7 @@ def request_raw(self, method, url, params=None, supplied_headers=None):
 
         abs_url = '%s%s' % (self.api_base, url)
 
-        encoded_params = urllib.urlencode(list(_api_encode(params or {})))
+        encoded_params = urlencode(list(_api_encode(params or {})))
 
         if method == 'get' or method == 'delete':
             if params:
@@ -326,7 +327,7 @@ def request_raw(self, method, url, params=None, supplied_headers=None):
         headers = self.request_headers(my_api_key, method)
 
         if supplied_headers is not None:
-            for key, value in supplied_headers.items():
+            for key, value in six.iteritems(supplied_headers):
                 headers[key] = value
 
         util.log_info('Request to Stripe api', method=method, path=abs_url)
diff --git a/stripe/api_resources/abstract/api_resource.py b/stripe/api_resources/abstract/api_resource.py
index 0bf71ba66..49ca78bd3 100644
--- a/stripe/api_resources/abstract/api_resource.py
+++ b/stripe/api_resources/abstract/api_resource.py
@@ -1,4 +1,5 @@
-import urllib
+import six
+from six.moves.urllib.parse import quote_plus
 
 from stripe import error, util
 from stripe.stripe_object import StripeObject
@@ -22,7 +23,7 @@ def class_name(cls):
             raise NotImplementedError(
                 'APIResource is an abstract class.  You should perform '
                 'actions on its subclasses (e.g. Charge, Customer)')
-        return str(urllib.quote_plus(cls.__name__.lower()))
+        return str(quote_plus(cls.__name__.lower()))
 
     @classmethod
     def class_url(cls):
@@ -32,7 +33,7 @@ def class_url(cls):
     def instance_url(self):
         id = self.get('id')
 
-        if not isinstance(id, basestring):
+        if not isinstance(id, six.string_types):
             raise error.InvalidRequestError(
                 'Could not determine which URL to request: %s instance '
                 'has invalid ID: %r, %s. ID should be of type `str` (or'
@@ -40,5 +41,5 @@ def instance_url(self):
 
         id = util.utf8(id)
         base = self.class_url()
-        extn = urllib.quote_plus(id)
+        extn = quote_plus(id)
         return "%s/%s" % (base, extn)
diff --git a/stripe/api_resources/abstract/nested_resource_class_methods.py b/stripe/api_resources/abstract/nested_resource_class_methods.py
index 8048143bc..4bed69840 100644
--- a/stripe/api_resources/abstract/nested_resource_class_methods.py
+++ b/stripe/api_resources/abstract/nested_resource_class_methods.py
@@ -1,4 +1,4 @@
-import urllib
+from six.moves.urllib.parse import quote_plus
 
 from stripe import api_requestor, util
 
@@ -11,10 +11,10 @@ def nested_resource_class_methods(resource, path=None, operations=None):
 
     def wrapper(cls):
         def nested_resource_url(cls, id, nested_id=None):
-            url = "%s/%s/%s" % (cls.class_url(), urllib.quote_plus(id),
-                                urllib.quote_plus(path))
+            url = "%s/%s/%s" % (cls.class_url(), quote_plus(id),
+                                quote_plus(path))
             if nested_id is not None:
-                url += "/%s" % urllib.quote_plus(nested_id)
+                url += "/%s" % quote_plus(nested_id)
             return url
         resource_url_method = "%ss_url" % resource
         setattr(cls, resource_url_method, classmethod(nested_resource_url))
diff --git a/stripe/api_resources/abstract/updateable_api_resource.py b/stripe/api_resources/abstract/updateable_api_resource.py
index 159b0a672..adc2bb7c1 100644
--- a/stripe/api_resources/abstract/updateable_api_resource.py
+++ b/stripe/api_resources/abstract/updateable_api_resource.py
@@ -1,4 +1,4 @@
-import urllib
+from six.moves.urllib.parse import quote_plus
 
 from stripe import api_requestor, util
 from stripe.api_resources.abstract.api_resource import APIResource
@@ -19,7 +19,7 @@ def _modify(cls, url, api_key=None, idempotency_key=None,
 
     @classmethod
     def modify(cls, sid, **params):
-        url = "%s/%s" % (cls.class_url(), urllib.quote_plus(util.utf8(sid)))
+        url = "%s/%s" % (cls.class_url(), quote_plus(util.utf8(sid)))
         return cls._modify(url, **params)
 
     def save(self, idempotency_key=None):
diff --git a/stripe/api_resources/account.py b/stripe/api_resources/account.py
index a5bdd1e94..ae38f3631 100644
--- a/stripe/api_resources/account.py
+++ b/stripe/api_resources/account.py
@@ -1,4 +1,4 @@
-import urllib
+from six.moves.urllib.parse import quote_plus
 
 from stripe import oauth, util
 from stripe.api_resources.abstract import CreateableAPIResource
@@ -33,7 +33,7 @@ def _build_instance_url(cls, sid):
             return "/v1/account"
         sid = util.utf8(sid)
         base = cls.class_url()
-        extn = urllib.quote_plus(sid)
+        extn = quote_plus(sid)
         return "%s/%s" % (base, extn)
 
     def instance_url(self):
diff --git a/stripe/api_resources/alipay_account.py b/stripe/api_resources/alipay_account.py
index 6b2624258..14b08e200 100644
--- a/stripe/api_resources/alipay_account.py
+++ b/stripe/api_resources/alipay_account.py
@@ -1,4 +1,4 @@
-import urllib
+from six.moves.urllib.parse import quote_plus
 
 from stripe import util
 from stripe.api_resources.customer import Customer
@@ -12,11 +12,11 @@ class AlipayAccount(UpdateableAPIResource, DeletableAPIResource):
     @classmethod
     def _build_instance_url(cls, customer, sid):
         token = util.utf8(sid)
-        extn = urllib.quote_plus(token)
+        extn = quote_plus(token)
         customer = util.utf8(customer)
 
         base = Customer.class_url()
-        owner_extn = urllib.quote_plus(customer)
+        owner_extn = quote_plus(customer)
 
         return "%s/%s/sources/%s" % (base, owner_extn, extn)
 
diff --git a/stripe/api_resources/application_fee_refund.py b/stripe/api_resources/application_fee_refund.py
index ef8748be4..d2d48a580 100644
--- a/stripe/api_resources/application_fee_refund.py
+++ b/stripe/api_resources/application_fee_refund.py
@@ -1,4 +1,4 @@
-import urllib
+from six.moves.urllib.parse import quote_plus
 
 from stripe import util
 from stripe.api_resources import ApplicationFee
@@ -13,8 +13,8 @@ def _build_instance_url(cls, fee, sid):
         fee = util.utf8(fee)
         sid = util.utf8(sid)
         base = ApplicationFee.class_url()
-        cust_extn = urllib.quote_plus(fee)
-        extn = urllib.quote_plus(sid)
+        cust_extn = quote_plus(fee)
+        extn = quote_plus(sid)
         return "%s/%s/refunds/%s" % (base, cust_extn, extn)
 
     @classmethod
diff --git a/stripe/api_resources/bank_account.py b/stripe/api_resources/bank_account.py
index 0cc435b14..fa6afaa94 100644
--- a/stripe/api_resources/bank_account.py
+++ b/stripe/api_resources/bank_account.py
@@ -1,4 +1,4 @@
-import urllib
+from six.moves.urllib.parse import quote_plus
 
 from stripe import error, util
 from stripe.api_resources.account import Account
@@ -13,19 +13,19 @@ class BankAccount(UpdateableAPIResource, DeletableAPIResource, VerifyMixin):
 
     def instance_url(self):
         token = util.utf8(self.id)
-        extn = urllib.quote_plus(token)
+        extn = quote_plus(token)
         if hasattr(self, 'customer'):
             customer = util.utf8(self.customer)
 
             base = Customer.class_url()
-            owner_extn = urllib.quote_plus(customer)
+            owner_extn = quote_plus(customer)
             class_base = "sources"
 
         elif hasattr(self, 'account'):
             account = util.utf8(self.account)
 
             base = Account.class_url()
-            owner_extn = urllib.quote_plus(account)
+            owner_extn = quote_plus(account)
             class_base = "external_accounts"
 
         else:
diff --git a/stripe/api_resources/bitcoin_receiver.py b/stripe/api_resources/bitcoin_receiver.py
index 78de6424e..5cef7edc1 100644
--- a/stripe/api_resources/bitcoin_receiver.py
+++ b/stripe/api_resources/bitcoin_receiver.py
@@ -1,4 +1,4 @@
-import urllib
+from six.moves.urllib.parse import quote_plus
 
 from stripe import util
 from stripe.api_resources.customer import Customer
@@ -14,12 +14,12 @@ class BitcoinReceiver(CreateableAPIResource, UpdateableAPIResource,
 
     def instance_url(self):
         token = util.utf8(self.id)
-        extn = urllib.quote_plus(token)
+        extn = quote_plus(token)
 
         if hasattr(self, 'customer'):
             customer = util.utf8(self.customer)
             base = Customer.class_url()
-            cust_extn = urllib.quote_plus(customer)
+            cust_extn = quote_plus(customer)
             return "%s/%s/sources/%s" % (base, cust_extn, extn)
         else:
             base = BitcoinReceiver.class_url()
diff --git a/stripe/api_resources/card.py b/stripe/api_resources/card.py
index 76e86297e..4150204b4 100644
--- a/stripe/api_resources/card.py
+++ b/stripe/api_resources/card.py
@@ -1,4 +1,4 @@
-import urllib
+from six.moves.urllib.parse import quote_plus
 
 from stripe import error, util
 from stripe.api_resources.account import Account
@@ -13,26 +13,26 @@ class Card(UpdateableAPIResource, DeletableAPIResource):
 
     def instance_url(self):
         token = util.utf8(self.id)
-        extn = urllib.quote_plus(token)
+        extn = quote_plus(token)
         if hasattr(self, 'customer'):
             customer = util.utf8(self.customer)
 
             base = Customer.class_url()
-            owner_extn = urllib.quote_plus(customer)
+            owner_extn = quote_plus(customer)
             class_base = "sources"
 
         elif hasattr(self, 'recipient'):
             recipient = util.utf8(self.recipient)
 
             base = Recipient.class_url()
-            owner_extn = urllib.quote_plus(recipient)
+            owner_extn = quote_plus(recipient)
             class_base = "cards"
 
         elif hasattr(self, 'account'):
             account = util.utf8(self.account)
 
             base = Account.class_url()
-            owner_extn = urllib.quote_plus(account)
+            owner_extn = quote_plus(account)
             class_base = "external_accounts"
 
         else:
diff --git a/stripe/api_resources/list_object.py b/stripe/api_resources/list_object.py
index 1672ab3cd..a9afb5793 100644
--- a/stripe/api_resources/list_object.py
+++ b/stripe/api_resources/list_object.py
@@ -1,6 +1,7 @@
-import urllib
 import warnings
 
+from six.moves.urllib.parse import quote_plus
+
 from stripe import util
 from stripe.stripe_object import StripeObject
 
@@ -41,7 +42,7 @@ def create(self, idempotency_key=None, **params):
     def retrieve(self, id, **params):
         base = self.get('url')
         id = util.utf8(id)
-        extn = urllib.quote_plus(id)
+        extn = quote_plus(id)
         url = "%s/%s" % (base, extn)
 
         return self.request('get', url, params)
diff --git a/stripe/api_resources/reversal.py b/stripe/api_resources/reversal.py
index 61cbf4d49..f267fb9bd 100644
--- a/stripe/api_resources/reversal.py
+++ b/stripe/api_resources/reversal.py
@@ -1,4 +1,4 @@
-import urllib
+from six.moves.urllib.parse import quote_plus
 
 from stripe import util
 from stripe.api_resources.transfer import Transfer
@@ -12,8 +12,8 @@ def instance_url(self):
         token = util.utf8(self.id)
         transfer = util.utf8(self.transfer)
         base = Transfer.class_url()
-        cust_extn = urllib.quote_plus(transfer)
-        extn = urllib.quote_plus(token)
+        cust_extn = quote_plus(transfer)
+        extn = quote_plus(token)
         return "%s/%s/reversals/%s" % (base, cust_extn, extn)
 
     @classmethod
diff --git a/stripe/api_resources/source.py b/stripe/api_resources/source.py
index 11ac7ba3b..5cecedbdf 100644
--- a/stripe/api_resources/source.py
+++ b/stripe/api_resources/source.py
@@ -1,6 +1,7 @@
-import urllib
 import warnings
 
+from six.moves.urllib.parse import quote_plus
+
 from stripe import util
 from stripe.api_resources import Customer
 from stripe.api_resources.abstract import CreateableAPIResource
@@ -13,10 +14,10 @@ class Source(CreateableAPIResource, UpdateableAPIResource, VerifyMixin):
 
     def detach(self, **params):
         if hasattr(self, 'customer') and self.customer:
-            extn = urllib.quote_plus(util.utf8(self.id))
+            extn = quote_plus(util.utf8(self.id))
             customer = util.utf8(self.customer)
             base = Customer.class_url()
-            owner_extn = urllib.quote_plus(customer)
+            owner_extn = quote_plus(customer)
             url = "%s/%s/sources/%s" % (base, owner_extn, extn)
 
             self.refresh_from(self.request('delete', url, params))
diff --git a/stripe/error.py b/stripe/error.py
index 748c51e52..4a6194db7 100644
--- a/stripe/error.py
+++ b/stripe/error.py
@@ -1,5 +1,5 @@
 # Exceptions
-import sys
+import six
 
 
 class StripeError(Exception):
@@ -29,7 +29,7 @@ def __unicode__(self):
         else:
             return self._message
 
-    if sys.version_info > (3, 0):
+    if six.PY3:
         def __str__(self):
             return self.__unicode__()
     else:
diff --git a/stripe/http_client.py b/stripe/http_client.py
index 3b6f4d0e6..c929fafa5 100644
--- a/stripe/http_client.py
+++ b/stripe/http_client.py
@@ -4,6 +4,8 @@
 import warnings
 import email
 
+import six
+
 from stripe import error, util
 
 # - Requests is the preferred HTTP library
@@ -11,7 +13,7 @@
 # - Use Pycurl if it's there (at least it verifies SSL certs)
 # - Fall back to urllib2 with a warning if needed
 try:
-    import urllib2
+    from six.moves import urllib
 except ImportError:
     # Try to load in urllib2, but don't sweat it if it's not available.
     pass
@@ -52,7 +54,7 @@
     urlfetch = None
 
 # proxy support for the pycurl client
-from urlparse import urlparse
+from six.moves.urllib.parse import urlparse
 
 
 def new_default_http_client(*args, **kwargs):
@@ -240,7 +242,7 @@ def parse_headers(self, data):
             return {}
         raw_headers = data.split('\r\n', 1)[1]
         headers = email.message_from_string(raw_headers)
-        return dict((k.lower(), v) for k, v in dict(headers).iteritems())
+        return dict((k.lower(), v) for k, v in six.iteritems(dict(headers)))
 
     def request(self, method, url, headers, post_data=None):
         b = util.io.BytesIO()
@@ -281,8 +283,10 @@ def request(self, method, url, headers, post_data=None):
         self._curl.setopt(pycurl.NOSIGNAL, 1)
         self._curl.setopt(pycurl.CONNECTTIMEOUT, 30)
         self._curl.setopt(pycurl.TIMEOUT, 80)
-        self._curl.setopt(pycurl.HTTPHEADER, ['%s: %s' % (k, v)
-                                              for k, v in headers.iteritems()])
+        self._curl.setopt(
+            pycurl.HTTPHEADER,
+            ['%s: %s' % (k, v) for k, v in six.iteritems(dict(headers))]
+        )
         if self._verify_ssl_certs:
             self._curl.setopt(pycurl.CAINFO, os.path.join(
                 os.path.dirname(__file__), 'data/ca-certificates.crt'))
@@ -335,10 +339,7 @@ def _get_proxy(self, url):
 
 
 class Urllib2Client(HTTPClient):
-    if sys.version_info >= (3, 0):
-        name = 'urllib.request'
-    else:
-        name = 'urllib2'
+    name = 'urllib.request'
 
     def __init__(self, verify_ssl_certs=True, proxy=None):
         super(Urllib2Client, self).__init__(
@@ -346,14 +347,14 @@ def __init__(self, verify_ssl_certs=True, proxy=None):
         # prepare and cache proxy tied opener here
         self._opener = None
         if self._proxy:
-            proxy = urllib2.ProxyHandler(self._proxy)
-            self._opener = urllib2.build_opener(proxy)
+            proxy = urllib.request.ProxyHandler(self._proxy)
+            self._opener = urllib.request.build_opener(proxy)
 
     def request(self, method, url, headers, post_data=None):
-        if sys.version_info >= (3, 0) and isinstance(post_data, basestring):
+        if six.PY3 and isinstance(post_data, six.string_types):
             post_data = post_data.encode('utf-8')
 
-        req = urllib2.Request(url, post_data, headers)
+        req = urllib.request.Request(url, post_data, headers)
 
         if method not in ('get', 'post'):
             req.get_method = lambda: method.upper()
@@ -363,17 +364,17 @@ def request(self, method, url, headers, post_data=None):
             # otherwise, fall to the default urllib opener.
             response = self._opener.open(req) \
                 if self._opener \
-                else urllib2.urlopen(req)
+                else urllib.request.urlopen(req)
             rbody = response.read()
             rcode = response.code
             headers = dict(response.info())
-        except urllib2.HTTPError as e:
+        except urllib.error.HTTPError as e:
             rcode = e.code
             rbody = e.read()
             headers = dict(e.info())
-        except (urllib2.URLError, ValueError) as e:
+        except (urllib.error.URLError, ValueError) as e:
             self._handle_request_error(e)
-        lh = dict((k.lower(), v) for k, v in dict(headers).iteritems())
+        lh = dict((k.lower(), v) for k, v in six.iteritems(dict(headers)))
         return rbody, rcode, lh
 
     def _handle_request_error(self, e):
diff --git a/stripe/multipart_data_generator.py b/stripe/multipart_data_generator.py
index d07d5d4ab..46fe108e5 100644
--- a/stripe/multipart_data_generator.py
+++ b/stripe/multipart_data_generator.py
@@ -1,7 +1,8 @@
 import random
-import sys
 import io
 
+import six
+
 
 class MultipartDataGenerator(object):
     def __init__(self, chunk_size=1028):
@@ -11,7 +12,7 @@ def __init__(self, chunk_size=1028):
         self.chunk_size = chunk_size
 
     def add_params(self, params):
-        for key, value in params.iteritems():
+        for key, value in six.iteritems(params):
             if value is None:
                 continue
 
@@ -50,7 +51,7 @@ def get_post_data(self):
         return self.data.getvalue()
 
     def _write(self, value):
-        if sys.version_info < (3,):
+        if six.PY2:
             binary_type = str
             text_type = unicode
         else:
diff --git a/stripe/oauth.py b/stripe/oauth.py
index 0e63fd7d6..9d9ad4332 100644
--- a/stripe/oauth.py
+++ b/stripe/oauth.py
@@ -1,4 +1,4 @@
-import urllib
+from six.moves.urllib.parse import urlencode
 
 from stripe import api_requestor, connect_api_base, error
 
@@ -30,7 +30,7 @@ def authorize_url(**params):
         OAuth._set_client_id(params)
         if 'response_type' not in params:
             params['response_type'] = 'code'
-        query = urllib.urlencode(list(api_requestor._api_encode(params)))
+        query = urlencode(list(api_requestor._api_encode(params)))
         url = connect_api_base + path + '?' + query
         return url
 
diff --git a/stripe/stripe_object.py b/stripe/stripe_object.py
index b86435369..b43c8b6e7 100644
--- a/stripe/stripe_object.py
+++ b/stripe/stripe_object.py
@@ -1,7 +1,8 @@
-import sys
 import warnings
 from copy import deepcopy
 
+import six
+
 import stripe
 from stripe import api_requestor, util
 
@@ -104,7 +105,7 @@ def __getitem__(self, k):
                     "the result returned by Stripe's API, probably as a "
                     "result of a save().  The attributes currently "
                     "available on this object are: %s" %
-                    (k, k, ', '.join(self.keys())))
+                    (k, k, ', '.join(list(self.keys()))))
             else:
                 raise err
 
@@ -169,7 +170,7 @@ def refresh_from(self, values, api_key=None, partial=False,
 
         self._transient_values = self._transient_values - set(values)
 
-        for k, v in values.iteritems():
+        for k, v in six.iteritems(values):
             super(StripeObject, self).__setitem__(
                 k, util.convert_to_stripe_object(v, api_key, stripe_version,
                                                  stripe_account))
@@ -195,16 +196,16 @@ def request(self, method, url, params=None, headers=None):
     def __repr__(self):
         ident_parts = [type(self).__name__]
 
-        if isinstance(self.get('object'), basestring):
+        if isinstance(self.get('object'), six.string_types):
             ident_parts.append(self.get('object'))
 
-        if isinstance(self.get('id'), basestring):
+        if isinstance(self.get('id'), six.string_types):
             ident_parts.append('id=%s' % (self.get('id'),))
 
         unicode_repr = '<%s at %s> JSON: %s' % (
             ' '.join(ident_parts), hex(id(self)), str(self))
 
-        if sys.version_info[0] < 3:
+        if six.PY2:
             return unicode_repr.encode('utf-8')
         else:
             return unicode_repr
@@ -230,7 +231,7 @@ def serialize(self, previous):
         unsaved_keys = self._unsaved_values or set()
         previous = previous or self._previous or {}
 
-        for k, v in self.items():
+        for k, v in six.iteritems(self):
             if k == 'id' or (isinstance(k, str) and k.startswith('_')):
                 continue
             elif isinstance(v, stripe.api_resources.abstract.APIResource):
@@ -256,7 +257,7 @@ def __copy__(self):
 
         copied._retrieve_params = self._retrieve_params
 
-        for k, v in self.items():
+        for k, v in six.iteritems(self):
             # Call parent's __setitem__ to avoid checks that we've added in the
             # overridden version that can throw exceptions.
             super(StripeObject, copied).__setitem__(k, v)
@@ -272,7 +273,7 @@ def __deepcopy__(self, memo):
         copied = self.__copy__()
         memo[id(self)] = copied
 
-        for k, v in self.items():
+        for k, v in six.iteritems(self):
             # Call parent's __setitem__ to avoid checks that we've added in the
             # overridden version that can throw exceptions.
             super(StripeObject, copied).__setitem__(k, deepcopy(v, memo))
diff --git a/stripe/test/helper.py b/stripe/test/helper.py
index c28495803..b6e3222a0 100644
--- a/stripe/test/helper.py
+++ b/stripe/test/helper.py
@@ -2,9 +2,10 @@
 import os
 import random
 import string
-import sys
 import unittest2
 
+import six
+
 from mock import patch, Mock
 
 import stripe
@@ -54,12 +55,7 @@ def tearDown(self):
 
 
 class StripeUnitTestCase(StripeTestCase):
-    REQUEST_LIBRARIES = ['urlfetch', 'requests', 'pycurl']
-
-    if sys.version_info >= (3, 0):
-        REQUEST_LIBRARIES.append('urllib.request')
-    else:
-        REQUEST_LIBRARIES.append('urllib2')
+    REQUEST_LIBRARIES = ['urlfetch', 'requests', 'pycurl', 'urllib.request']
 
     def setUp(self):
         super(StripeUnitTestCase, self).setUp()
@@ -75,7 +71,7 @@ def setUp(self):
     def tearDown(self):
         super(StripeUnitTestCase, self).tearDown()
 
-        for patcher in self.request_patchers.itervalues():
+        for patcher in six.itervalues(self.request_patchers):
             patcher.stop()
 
 
diff --git a/stripe/test/test_api_requestor.py b/stripe/test/test_api_requestor.py
index b699b842d..053474eb9 100644
--- a/stripe/test/test_api_requestor.py
+++ b/stripe/test/test_api_requestor.py
@@ -1,6 +1,10 @@
+from __future__ import print_function
+
 import datetime
 import unittest2
-import urlparse
+
+import six
+from six.moves.urllib.parse import urlsplit
 
 from mock import Mock, ANY
 
@@ -49,7 +53,7 @@ def __eq__(self, other):
                 self._extra_match(other))
 
     def _keys_match(self, other):
-        expected_keys = list(set(self.EXP_KEYS + self.extra.keys()))
+        expected_keys = list(set(self.EXP_KEYS + list(self.extra.keys())))
         if self.request_method is not None and self.request_method in \
                 self.METHOD_EXTRA_KEYS:
             expected_keys.extend(self.METHOD_EXTRA_KEYS[self.request_method])
@@ -74,7 +78,7 @@ def _x_stripe_ua_contains_app_info(self, other):
         return True
 
     def _extra_match(self, other):
-        for k, v in self.extra.iteritems():
+        for k, v in six.iteritems(self.extra):
             if other[k] != v:
                 return False
 
@@ -87,7 +91,7 @@ def __init__(self, expected):
         self.expected = sorted(expected)
 
     def __eq__(self, other):
-        query = urlparse.urlsplit(other).query or other
+        query = urlsplit(other).query or other
 
         parsed = stripe.util.parse_qsl(query)
         return self.expected == sorted(parsed)
@@ -96,17 +100,17 @@ def __eq__(self, other):
 class UrlMatcher(object):
 
     def __init__(self, expected):
-        self.exp_parts = urlparse.urlsplit(expected)
+        self.exp_parts = urlsplit(expected)
 
     def __eq__(self, other):
-        other_parts = urlparse.urlsplit(other)
+        other_parts = urlsplit(other)
 
         for part in ('scheme', 'netloc', 'path', 'fragment'):
             expected = getattr(self.exp_parts, part)
             actual = getattr(other_parts, part)
             if expected != actual:
-                print 'Expected %s "%s" but got "%s"' % (
-                    part, expected, actual)
+                print('Expected %s "%s" but got "%s"' % (
+                    part, expected, actual))
                 return False
 
         q_matcher = QueryMatcher(stripe.util.parse_qsl(self.exp_parts.query))
@@ -222,7 +226,7 @@ def test_param_encoding(self):
         self.requestor.request('get', '', self.ENCODE_INPUTS)
 
         expectation = []
-        for type_, values in self.ENCODE_EXPECTATIONS.iteritems():
+        for type_, values in six.iteritems(self.ENCODE_EXPECTATIONS):
             expectation.extend([(k % (type_,), str(v)) for k, v in values])
 
         self.check_call('get', QueryMatcher(expectation))
diff --git a/stripe/test/test_error.py b/stripe/test/test_error.py
index 200bfe6a7..5fe502196 100644
--- a/stripe/test/test_error.py
+++ b/stripe/test/test_error.py
@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
-import sys
-
 import unittest2
 
+import six
+
 from stripe import StripeError
 from stripe.test.helper import StripeUnitTestCase
 
@@ -11,7 +11,7 @@ class StripeErrorTests(StripeUnitTestCase):
 
     def test_formatting(self):
         err = StripeError(u'öre')
-        if sys.version_info > (3, 0):
+        if six.PY3:
             assert str(err) == u'öre'
         else:
             assert str(err) == '\xc3\xb6re'
@@ -19,7 +19,7 @@ def test_formatting(self):
 
     def test_formatting_with_request_id(self):
         err = StripeError(u'öre', headers={'request-id': '123'})
-        if sys.version_info > (3, 0):
+        if six.PY3:
             assert str(err) == u'Request 123: öre'
         else:
             assert str(err) == 'Request 123: \xc3\xb6re'
@@ -27,7 +27,7 @@ def test_formatting_with_request_id(self):
 
     def test_formatting_with_none(self):
         err = StripeError(None, headers={'request-id': '123'})
-        if sys.version_info > (3, 0):
+        if six.PY3:
             assert str(err) == u'Request 123: <empty message>'
         else:
             assert str(err) == 'Request 123: <empty message>'
diff --git a/stripe/test/test_http_client.py b/stripe/test/test_http_client.py
index 2cc5be4ca..d9180d40c 100644
--- a/stripe/test/test_http_client.py
+++ b/stripe/test/test_http_client.py
@@ -1,8 +1,9 @@
-import sys
 import unittest2
 
 from mock import MagicMock, Mock, patch
 
+import six
+
 import stripe
 
 from stripe.test.helper import StripeUnitTestCase
@@ -219,7 +220,7 @@ def mock_error(self, mock):
         mock.build_opener.reset_mock()
 
     def check_call(self, mock, meth, url, post_data, headers):
-        if sys.version_info >= (3, 0) and isinstance(post_data, basestring):
+        if six.PY3 and isinstance(post_data, six.string_types):
             post_data = post_data.encode('utf-8')
 
         mock.Request.assert_called_with(url, post_data, headers)
diff --git a/stripe/test/test_integration.py b/stripe/test/test_integration.py
index ca1dc720f..58fc09f5b 100644
--- a/stripe/test/test_integration.py
+++ b/stripe/test/test_integration.py
@@ -1,9 +1,10 @@
 # -*- coding: utf-8 -*-
 import os
-import sys
 import unittest2
 import stripe
 
+import six
+
 from mock import patch
 from stripe.test.helper import (StripeTestCase, DUMMY_CHARGE)
 
@@ -106,7 +107,7 @@ class PycurlFunctionalTests(FunctionalTests):
     def setUp(self):
         if not os.environ.get('STRIPE_TEST_PYCURL'):
             self.skipTest('Pycurl skipped as STRIPE_TEST_PYCURL is not set')
-        if sys.version_info >= (3, 0):
+        if six.PY3:
             self.skipTest('Pycurl is not supported in Python 3')
         else:
             super(PycurlFunctionalTests, self).setUp()
@@ -123,7 +124,7 @@ def test_invalid_credentials(self):
             stripe.Customer.create()
         except stripe.error.AuthenticationError as e:
             self.assertEqual(401, e.http_status)
-            self.assertTrue(isinstance(e.http_body, basestring))
+            self.assertTrue(isinstance(e.http_body, six.string_types))
             self.assertTrue(isinstance(e.json_body, dict))
             # Note that an invalid API key bypasses many of the standard
             # facilities in the API server so currently no Request ID is
@@ -140,7 +141,7 @@ def test_declined_card_props(self):
                                  source='tok_chargeDeclinedExpiredCard')
         except stripe.error.CardError as e:
             self.assertEqual(402, e.http_status)
-            self.assertTrue(isinstance(e.http_body, basestring))
+            self.assertTrue(isinstance(e.http_body, six.string_types))
             self.assertTrue(isinstance(e.json_body, dict))
             self.assertTrue(e.request_id.startswith('req_'))
 
@@ -152,7 +153,7 @@ def test_nonexistent_object(self):
             stripe.Charge.retrieve('invalid')
         except stripe.error.InvalidRequestError as e:
             self.assertEqual(404, e.http_status)
-            self.assertTrue(isinstance(e.http_body, basestring))
+            self.assertTrue(isinstance(e.http_body, six.string_types))
             self.assertTrue(isinstance(e.json_body, dict))
             self.assertTrue(e.request_id.startswith('req_'))
 
@@ -161,7 +162,7 @@ def test_invalid_data(self):
             stripe.Charge.create()
         except stripe.error.InvalidRequestError as e:
             self.assertEqual(400, e.http_status)
-            self.assertTrue(isinstance(e.http_body, basestring))
+            self.assertTrue(isinstance(e.http_body, six.string_types))
             self.assertTrue(isinstance(e.json_body, dict))
             self.assertTrue(e.request_id.startswith('req_'))
 
diff --git a/stripe/test/test_multipart_data_generator.py b/stripe/test/test_multipart_data_generator.py
index 94a909e2f..a2488df43 100644
--- a/stripe/test/test_multipart_data_generator.py
+++ b/stripe/test/test_multipart_data_generator.py
@@ -1,8 +1,8 @@
 # -*- encoding: utf-8 -*-
 
 import re
-import sys
-import StringIO
+
+import six
 
 from stripe.multipart_data_generator import MultipartDataGenerator
 from stripe.test.helper import StripeTestCase
@@ -20,7 +20,7 @@ def run_test_multipart_data_with_file(self, test_file):
         generator.add_params(params)
         http_body = generator.get_post_data()
 
-        if sys.version_info >= (3,):
+        if six.PY3:
             http_body = http_body.decode('utf-8')
 
         self.assertTrue(re.search(
@@ -39,7 +39,7 @@ def run_test_multipart_data_with_file(self, test_file):
         test_file.seek(0)
         file_contents = test_file.read()
 
-        if sys.version_info >= (3,) and isinstance(file_contents, bytes):
+        if six.PY3 and isinstance(file_contents, bytes):
             file_contents = file_contents.decode('utf-8')
 
         self.assertNotEqual(-1, http_body.find(file_contents))
@@ -53,5 +53,5 @@ def test_multipart_data_file_binary(self):
             self.run_test_multipart_data_with_file(test_file)
 
     def test_multipart_data_stringio(self):
-        string = StringIO.StringIO("foo")
+        string = six.StringIO("foo")
         self.run_test_multipart_data_with_file(string)
diff --git a/stripe/test/test_oauth.py b/stripe/test/test_oauth.py
index 6175118e9..d69846022 100644
--- a/stripe/test/test_oauth.py
+++ b/stripe/test/test_oauth.py
@@ -1,4 +1,4 @@
-import urlparse
+from six.moves.urllib.parse import parse_qs, urlparse
 
 import stripe
 from stripe.test.helper import StripeApiTestCase
@@ -26,8 +26,8 @@ def test_authorize_url(self):
                 'country': 'US',
             })
 
-        o = urlparse.urlparse(url)
-        params = urlparse.parse_qs(o.query)
+        o = urlparse(url)
+        params = parse_qs(o.query)
 
         self.assertEqual('https', o.scheme)
         self.assertEqual('connect.stripe.com', o.netloc)
diff --git a/stripe/test/test_stripe_object.py b/stripe/test/test_stripe_object.py
index c60aca631..679324b6c 100644
--- a/stripe/test/test_stripe_object.py
+++ b/stripe/test/test_stripe_object.py
@@ -1,7 +1,8 @@
 import pickle
-import sys
 from copy import copy, deepcopy
 
+import six
+
 import stripe
 from stripe import util
 from stripe.test.helper import StripeUnitTestCase
@@ -160,8 +161,8 @@ def test_to_json(self):
 
     def check_invoice_data(self, data):
         # Check rough structure
-        self.assertEqual(20, len(data.keys()))
-        self.assertEqual(3, len(data['lines'].keys()))
+        self.assertEqual(20, len(list(data.keys())))
+        self.assertEqual(3, len(list(data['lines'].keys())))
         self.assertEqual(0, len(data['lines']['invoiceitems']))
         self.assertEqual(1, len(data['lines']['subscriptions']))
 
@@ -180,7 +181,7 @@ def test_repr(self):
 
         res = repr(obj)
 
-        if sys.version_info[0] < 3:
+        if six.PY2:
             res = unicode(repr(obj), 'utf-8')
 
         self.assertTrue(u'<StripeObject \u4e00boo\u1f00' in res)
diff --git a/stripe/test/test_util.py b/stripe/test/test_util.py
index 86109f272..b7a884e42 100644
--- a/stripe/test/test_util.py
+++ b/stripe/test/test_util.py
@@ -11,9 +11,9 @@
 from stripe import util
 from stripe.test.helper import StripeUnitTestCase
 
-import __builtin__
+from six.moves import builtins
 
-PRINT_FUNC_STRING = __builtin__.__name__ + '.print'
+PRINT_FUNC_STRING = builtins.__name__ + '.print'
 
 LogTestCase = namedtuple('LogTestCase', 'env flag should_output')
 FmtTestCase = namedtuple('FmtTestCase', 'props expected')
diff --git a/stripe/test/test_webhook.py b/stripe/test/test_webhook.py
index d2c3411d8..33a78db35 100644
--- a/stripe/test/test_webhook.py
+++ b/stripe/test/test_webhook.py
@@ -1,6 +1,7 @@
-import sys
 import time
 
+import six
+
 import stripe
 from stripe.test.helper import StripeUnitTestCase
 
@@ -43,7 +44,7 @@ def test_construct_event_from_bytearray(self):
     def test_construct_event_from_bytes(self):
         # This test is only applicable to Python 3 as `bytes` is not a symbol
         # in Python 2.
-        if sys.version_info < (3, 0):
+        if six.PY2:
             return
 
         header = WebhookSignatureTests.generate_header()
@@ -70,7 +71,7 @@ def generate_header(**kwargs):
 
     def test_raise_on_malformed_header(self):
         header = "i'm not even a real signature header"
-        with self.assertRaisesRegexp(
+        with self.assertRaisesRegex(
                 stripe.error.SignatureVerificationError,
                 "Unable to extract timestamp and signatures from header"):
             stripe.WebhookSignature.verify_header(
@@ -78,7 +79,7 @@ def test_raise_on_malformed_header(self):
 
     def test_raise_on_no_signatures_with_expected_scheme(self):
         header = self.generate_header(scheme='v0')
-        with self.assertRaisesRegexp(
+        with self.assertRaisesRegex(
                 stripe.error.SignatureVerificationError,
                 "No signatures found with expected scheme v1"):
             stripe.WebhookSignature.verify_header(
@@ -86,7 +87,7 @@ def test_raise_on_no_signatures_with_expected_scheme(self):
 
     def test_raise_on_no_valid_signatures_for_payload(self):
         header = self.generate_header(signature='bad_signature')
-        with self.assertRaisesRegexp(
+        with self.assertRaisesRegex(
                 stripe.error.SignatureVerificationError,
                 "No signatures found matching the expected signature for "
                 "payload"):
@@ -95,7 +96,7 @@ def test_raise_on_no_valid_signatures_for_payload(self):
 
     def test_raise_on_timestamp_outside_tolerance(self):
         header = self.generate_header(timestamp=int(time.time()) - 15)
-        with self.assertRaisesRegexp(
+        with self.assertRaisesRegex(
                 stripe.error.SignatureVerificationError,
                 "Timestamp outside the tolerance zone"):
             stripe.WebhookSignature.verify_header(
diff --git a/stripe/util.py b/stripe/util.py
index 10177e32c..0e67b4219 100644
--- a/stripe/util.py
+++ b/stripe/util.py
@@ -7,6 +7,8 @@
 import os
 import re
 
+import six
+
 import stripe
 
 
@@ -26,7 +28,7 @@
 ]
 
 try:
-    from urlparse import parse_qsl
+    from six.moves.urllib.parse import parse_qsl
 except ImportError:
     # Python < 2.6
     from cgi import parse_qsl
@@ -62,7 +64,7 @@ def utf8(value):
     # Note the ordering of these conditionals: `unicode` isn't a symbol in
     # Python 3 so make sure to check version before trying to use it. Python
     # 2to3 will also boil out `unicode`.
-    if sys.version_info < (3, 0) and isinstance(value, unicode):
+    if six.PY2 and isinstance(value, unicode):
         return value.encode('utf-8')
     else:
         return value
@@ -115,14 +117,14 @@ def dashboard_link(request_id):
 def logfmt(props):
     def fmt(key, val):
         # Handle case where val is a bytes or bytesarray
-        if sys.version_info[0] == 3 and hasattr(val, 'decode'):
+        if six.PY3 and hasattr(val, 'decode'):
             val = val.decode('utf-8')
         # Check if val is already a string to avoid re-encoding into
         # ascii. Since the code is sent through 2to3, we can't just
         # use unicode(val, encoding='utf8') since it will be
         # translated incorrectly.
-        if not isinstance(val, basestring):
-            val = unicode(val)
+        if not isinstance(val, six.string_types):
+            val = six.text_type(val)
         if re.search(r'\s', val):
             val = repr(val)
         # key should already be a string
@@ -150,8 +152,7 @@ def secure_compare(val1, val2):
         if len(val1) != len(val2):
             return False
         result = 0
-        if (sys.version_info[0] == 3 and isinstance(val1, bytes) and
-                isinstance(val2, bytes)):
+        if six.PY3 and isinstance(val1, bytes) and isinstance(val2, bytes):
             for x, y in zip(val1, val2):
                 result |= x ^ y
         else:
@@ -239,7 +240,7 @@ def convert_to_stripe_object(resp, api_key=None, stripe_version=None,
             not isinstance(resp, stripe.stripe_object.StripeObject):
         resp = resp.copy()
         klass_name = resp.get('object')
-        if isinstance(klass_name, basestring):
+        if isinstance(klass_name, six.string_types):
             klass = types.get(klass_name, stripe.stripe_object.StripeObject)
         else:
             klass = stripe.stripe_object.StripeObject
diff --git a/stripe/webhook.py b/stripe/webhook.py
index c8ab16972..a5d29f487 100644
--- a/stripe/webhook.py
+++ b/stripe/webhook.py
@@ -35,7 +35,7 @@ def _compute_signature(payload, secret):
 
     @staticmethod
     def _get_timestamp_and_signatures(header, scheme):
-        list_items = map(lambda i: i.split('=', 2), header.split(','))
+        list_items = [i.split('=', 2) for i in header.split(',')]
         timestamp = int([i[1] for i in list_items if i[0] == 't'][0])
         signatures = [i[1] for i in list_items if i[0] == scheme]
         return timestamp, signatures