diff --git a/setup.py b/setup.py
index 50ed837..234f96e 100644
--- a/setup.py
+++ b/setup.py
@@ -12,13 +12,15 @@
     'Programming Language :: Python :: 2',
     'Programming Language :: Python :: 2.6',
     'Programming Language :: Python :: 2.7',
+    'Programming Language :: Python :: 3.6',
+    'Programming Language :: Python :: 3.7',
     'Topic :: System :: Systems Administration :: Authentication/Directory',
     'Topic :: System :: Systems Administration :: Authentication/Directory :: LDAP',
 ]
 
 setup(
     name="simpleldap",
-    version="0.8",
+    version="0.9",
     description="A module that makes simple LDAP usage simple.",
     long_description=open('README.rst').read(),
     keywords="ldap simple simpleldap",
@@ -28,5 +30,5 @@
     license="MIT",
     packages=["simpleldap"],
     install_requires=["python-ldap"],
-    tests_require=["tox", "pytest", "pep8", "python-ldap"],
+    tests_require=["tox", "pytest", "pycodestye", "python-ldap", "six"],
 )
diff --git a/simpleldap/__init__.py b/simpleldap/__init__.py
index 99500b6..3854c2e 100644
--- a/simpleldap/__init__.py
+++ b/simpleldap/__init__.py
@@ -50,7 +50,7 @@ def __init__(self, result):
         self.dn, self.attributes = result
         # XXX: quick and dirty, should really proxy straight to the existing
         # self.attributes dict.
-        for attribute, values in self.attributes.iteritems():
+        for attribute, values in self.attributes.items():
             # Make the entire list of values for each LDAP attribute
             # accessible through a dictionary mapping.
             self[attribute] = values
@@ -168,7 +168,7 @@ def __init__(self, hostname='localhost', port=None, dn='', password='',
         else:
             self.connection = ldap.initialize(uri)
         if options:
-            for name, value in options.iteritems():
+            for name, value in options.items():
                 self.connection.set_option(getattr(ldap, name), value)
         if encryption == 'tls':
             self.connection.start_tls_s()
diff --git a/simpleldap/cidict.py b/simpleldap/cidict.py
index 19cf374..0d0268f 100644
--- a/simpleldap/cidict.py
+++ b/simpleldap/cidict.py
@@ -32,7 +32,7 @@ def update(self, dict):
             self[key] = dict[key]
 
     def has_key(self, key):
-        return super(cidict, self).has_key(key.lower())
+        return key.lower() in super(cidict, self).keys()
 
     __contains__ = has_key
 
diff --git a/tests/tests.py b/tests/tests.py
index 2f4d119..78b809f 100644
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -3,6 +3,7 @@
 from unittest import TestCase
 
 import ldap
+from six import StringIO
 
 import simpleldap
 
@@ -25,14 +26,13 @@ def test_connect(self):
                 conn = simpleldap.Connection(hostname=host, port=port,
                                              encryption=method,
                                              require_cert=cert)
-            except Exception, e:
+            except Exception as e:
                 self.fail("Got error connecting to %s %s %s %s: %s"
                           % (host, port, method, cert, e))
             else:
                 conn.close()
 
     def test_initialize_kwargs(self):
-        from StringIO import StringIO
         output = StringIO()
         initialize_kwargs = {'trace_file': output, 'trace_level': 0}
         conn = simpleldap.Connection('ldap.utexas.edu',
@@ -107,7 +107,7 @@ def test_get(self):
         obj = conn.get('cn=External Anonymous',
                        base_dn='ou=Groups,dc=ucdavis,dc=edu')
         self.assertTrue(isinstance(obj, conn.result_item_class))
-        self.assertEqual(obj['cn'], ['External Anonymous'])
+        self.assertEqual(obj['cn'], [b'External Anonymous'])
 
         self.assertRaises(simpleldap.ObjectNotFound, conn.get,
                           'cn=Does not exist',
diff --git a/tox.ini b/tox.ini
index 102e8c7..2a7238d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,14 +1,13 @@
 [tox]
-envlist = py26, py27
-indexserver =
-    pypi = http://pypi.python.org/simple
+envlist = py26,py27,py36,py37
 
 [testenv]
 deps=
-    :pypi:python-ldap
-    :pypi:pytest
-    :pypi:pep8
+    python-ldap
+    pytest<5
+    pycodestyle
+    six
 
 commands =
     py.test -v tests/tests.py tests/cidict.py
-    pep8 --ignore=W601 simpleldap
+    pycodestyle --ignore=W601 simpleldap