diff --git a/flask/_compat.py b/flask/_compat.py
new file mode 100644
index 00000000..3743a54c
--- /dev/null
+++ b/flask/_compat.py
@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+"""
+    flask._compat
+    ~~~~~~~~~~~~~
+
+    Some py2/py3 compatibility support that is not yet available in
+    "six" 1.3.0.
+    There are bugs open for "six" for all this stuff, so we can remove it
+    again from here as soon as we require a new enough "six" release.
+
+    :copyright: (c) 2013 by Armin Ronacher.
+    :license: BSD, see LICENSE for more details.
+"""
diff --git a/flask/helpers.py b/flask/helpers.py
index d68cb04b..68ebc74e 100644
--- a/flask/helpers.py
+++ b/flask/helpers.py
@@ -26,6 +26,7 @@ from functools import update_wrapper
 
 from werkzeug.datastructures import Headers
 from werkzeug.exceptions import NotFound
+import six
 
 # this was moved in 0.7
 try:
@@ -128,7 +129,7 @@ def stream_with_context(generator_or_function):
     # pushed.  This item is discarded.  Then when the iteration continues the
     # real generator is executed.
     wrapped_g = generator()
-    wrapped_g.next()
+    six.advance_iterator(wrapped_g)
     return wrapped_g
 
 
diff --git a/flask/json.py b/flask/json.py
index 52e5680e..d5da4f91 100644
--- a/flask/json.py
+++ b/flask/json.py
@@ -17,6 +17,7 @@ from werkzeug.http import http_date
 # Use the same json implementation as itsdangerous on which we
 # depend anyways.
 from itsdangerous import simplejson as _json
+import six
 
 
 # figure out if simplejson escapes slashes.  This behavior was changed
@@ -59,7 +60,7 @@ class JSONEncoder(_json.JSONEncoder):
         if isinstance(o, uuid.UUID):
             return str(o)
         if hasattr(o, '__html__'):
-            return unicode(o.__html__())
+            return six.text_type(o.__html__())
         return _json.JSONEncoder.default(self, o)
 
 
diff --git a/flask/sessions.py b/flask/sessions.py
index 31b5900b..04b7f8af 100644
--- a/flask/sessions.py
+++ b/flask/sessions.py
@@ -17,6 +17,7 @@ from werkzeug.datastructures import CallbackDict
 from . import Markup, json
 
 from itsdangerous import URLSafeTimedSerializer, BadSignature
+import six
 
 
 def total_seconds(td):
@@ -62,16 +63,16 @@ class TaggedJSONSerializer(object):
             elif isinstance(value, uuid.UUID):
                 return {' u': value.hex}
             elif callable(getattr(value, '__html__', None)):
-                return {' m': unicode(value.__html__())}
+                return {' m': six.text_type(value.__html__())}
             elif isinstance(value, list):
                 return [_tag(x) for x in value]
             elif isinstance(value, datetime):
                 return {' d': http_date(value)}
             elif isinstance(value, dict):
-                return dict((k, _tag(v)) for k, v in value.iteritems())
+                return dict((k, _tag(v)) for k, v in six.iteritems(value))
             elif isinstance(value, str):
                 try:
-                    return unicode(value)
+                    return six.text_type(value)
                 except UnicodeError:
                     raise UnexpectedUnicodeError(u'A byte string with '
                         u'non-ASCII data was passed to the session system '
@@ -84,7 +85,7 @@ class TaggedJSONSerializer(object):
         def object_hook(obj):
             if len(obj) != 1:
                 return obj
-            the_key, the_value = obj.iteritems().next()
+            the_key, the_value = six.advance_iterator(obj.iteritems())
             if the_key == ' t':
                 return tuple(the_value)
             elif the_key == ' u':
diff --git a/flask/templating.py b/flask/templating.py
index 2cc09c4d..754c6893 100644
--- a/flask/templating.py
+++ b/flask/templating.py
@@ -15,6 +15,7 @@ from jinja2 import BaseLoader, Environment as BaseEnvironment, \
 from .globals import _request_ctx_stack, _app_ctx_stack
 from .signals import template_rendered
 from .module import blueprint_is_module
+import six
 
 
 def _default_template_ctx_processor():
@@ -79,7 +80,7 @@ class DispatchingJinjaLoader(BaseLoader):
         except (ValueError, KeyError):
             pass
 
-        for blueprint in self.app.blueprints.itervalues():
+        for blueprint in six.itervalues(self.app.blueprints):
             if blueprint_is_module(blueprint):
                 continue
             loader = blueprint.jinja_loader
@@ -92,7 +93,7 @@ class DispatchingJinjaLoader(BaseLoader):
         if loader is not None:
             result.update(loader.list_templates())
 
-        for name, blueprint in self.app.blueprints.iteritems():
+        for name, blueprint in six.iteritems(self.app.blueprints):
             loader = blueprint.jinja_loader
             if loader is not None:
                 for template in loader.list_templates():
diff --git a/flask/testsuite/__init__.py b/flask/testsuite/__init__.py
index 084b3726..9027369c 100644
--- a/flask/testsuite/__init__.py
+++ b/flask/testsuite/__init__.py
@@ -10,6 +10,7 @@
     :license: BSD, see LICENSE for more details.
 """
 
+from __future__ import print_function
 from __future__ import with_statement
 
 import os
@@ -221,4 +222,4 @@ def main():
     try:
         unittest.main(testLoader=BetterLoader(), defaultTest='suite')
     except Exception as e:
-        print 'Error: %s' % e
+        print('Error: %s' % e)
diff --git a/flask/testsuite/basic.py b/flask/testsuite/basic.py
index 2836a1b6..89159a16 100644
--- a/flask/testsuite/basic.py
+++ b/flask/testsuite/basic.py
@@ -22,6 +22,7 @@ from flask.testsuite import FlaskTestCase, emits_module_deprecation_warning
 from werkzeug.exceptions import BadRequest, NotFound
 from werkzeug.http import parse_date
 from werkzeug.routing import BuildError
+import six
 
 
 class BasicFunctionalityTestCase(FlaskTestCase):
@@ -277,7 +278,7 @@ class BasicFunctionalityTestCase(FlaskTestCase):
 
         @app.route('/test')
         def test():
-            return unicode(flask.session.permanent)
+            return six.text_type(flask.session.permanent)
 
         client = app.test_client()
         rv = client.get('/')
diff --git a/flask/testsuite/blueprints.py b/flask/testsuite/blueprints.py
index 0399d48e..eba43e63 100644
--- a/flask/testsuite/blueprints.py
+++ b/flask/testsuite/blueprints.py
@@ -18,6 +18,7 @@ from flask.testsuite import FlaskTestCase, emits_module_deprecation_warning
 from werkzeug.exceptions import NotFound
 from werkzeug.http import parse_cache_control_header
 from jinja2 import TemplateNotFound
+import six
 
 
 # import moduleapp here because it uses deprecated features and we don't
@@ -304,7 +305,7 @@ class BlueprintTestCase(FlaskTestCase):
 
         @bp.route('/bar')
         def bar(bar):
-            return unicode(bar)
+            return six.text_type(bar)
 
         app = flask.Flask(__name__)
         app.register_blueprint(bp, url_prefix='/1', url_defaults={'bar': 23})
diff --git a/flask/testsuite/config.py b/flask/testsuite/config.py
index 0b2c65bd..ca142cff 100644
--- a/flask/testsuite/config.py
+++ b/flask/testsuite/config.py
@@ -113,7 +113,7 @@ class LimitedLoaderMockWrapper(object):
     def __getattr__(self, name):
         if name in ('archive', 'get_filename'):
             msg = 'Mocking a loader which does not have `%s.`' % name
-            raise AttributeError, msg
+            raise AttributeError(msg)
         return getattr(self.loader, name)
 
 
diff --git a/flask/testsuite/ext.py b/flask/testsuite/ext.py
index 034ab5be..096a70f8 100644
--- a/flask/testsuite/ext.py
+++ b/flask/testsuite/ext.py
@@ -13,7 +13,7 @@ from __future__ import with_statement
 import sys
 import unittest
 from flask.testsuite import FlaskTestCase
-
+from six import reload_module
 
 class ExtImportHookTestCase(FlaskTestCase):
 
@@ -29,7 +29,7 @@ class ExtImportHookTestCase(FlaskTestCase):
                 entry == 'flaskext') and value is not None:
                 sys.modules.pop(entry, None)
         from flask import ext
-        reload(ext)
+        reload_module(ext)
 
         # reloading must not add more hooks
         import_hooks = 0
diff --git a/flask/testsuite/helpers.py b/flask/testsuite/helpers.py
index fdf2d89f..ac618538 100644
--- a/flask/testsuite/helpers.py
+++ b/flask/testsuite/helpers.py
@@ -18,6 +18,7 @@ from logging import StreamHandler
 from StringIO import StringIO
 from flask.testsuite import FlaskTestCase, catch_warnings, catch_stderr
 from werkzeug.http import parse_cache_control_header, parse_options_header
+import six
 
 
 def has_encoding(name):
@@ -35,7 +36,7 @@ class JSONTestCase(FlaskTestCase):
         app = flask.Flask(__name__)
         @app.route('/json', methods=['POST'])
         def return_json():
-            return unicode(flask.request.json)
+            return six.text_type(flask.request.json)
         c = app.test_client()
         rv = c.post('/json', data='malformed', content_type='application/json')
         self.assert_equal(rv.status_code, 400)
@@ -44,7 +45,7 @@ class JSONTestCase(FlaskTestCase):
         app = flask.Flask(__name__)
         @app.route('/json', methods=['POST'])
         def return_json():
-            return unicode(flask.request.json)
+            return six.text_type(flask.request.json)
         c = app.test_client()
         rv = c.post('/json', data='malformed', content_type='application/json')
         self.assert_equal(rv.status_code, 400)
@@ -96,7 +97,7 @@ class JSONTestCase(FlaskTestCase):
         app = flask.Flask(__name__)
         @app.route('/add', methods=['POST'])
         def add():
-            return unicode(flask.request.json['a'] + flask.request.json['b'])
+            return six.text_type(flask.request.json['a'] + flask.request.json['b'])
         c = app.test_client()
         rv = c.post('/add', data=flask.json.dumps({'a': 1, 'b': 2}),
                             content_type='application/json')
@@ -507,7 +508,7 @@ class StreamingTestCase(FlaskTestCase):
             def close(self):
                 called.append(42)
             def next(self):
-                return self._gen.next()
+                return six.advance_iterator(self._gen)
         @app.route('/')
         def index():
             def generate():
diff --git a/flask/testsuite/testing.py b/flask/testsuite/testing.py
index 605078a7..2872ecdc 100644
--- a/flask/testsuite/testing.py
+++ b/flask/testsuite/testing.py
@@ -14,6 +14,7 @@ from __future__ import with_statement
 import flask
 import unittest
 from flask.testsuite import FlaskTestCase
+import six
 
 
 class TestToolsTestCase(FlaskTestCase):
@@ -85,7 +86,7 @@ class TestToolsTestCase(FlaskTestCase):
 
         @app.route('/')
         def index():
-            return unicode(flask.session['foo'])
+            return six.text_type(flask.session['foo'])
 
         with app.test_client() as c:
             with c.session_transaction() as sess:
diff --git a/setup.py b/setup.py
index ba5f4a67..4ad0b546 100644
--- a/setup.py
+++ b/setup.py
@@ -90,6 +90,7 @@ setup(
     zip_safe=False,
     platforms='any',
     install_requires=[
+        'six>=1.3.0',
         'Werkzeug>=0.7',
         'Jinja2>=2.4',
         'itsdangerous>=0.17'