diff --git a/.travis.yml b/.travis.yml
index 9896b753c..fbfb621d2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -43,7 +43,7 @@ before_script:
 script:
   - python ./tests.py
   - cd test_project
-  - coverage run --source ../modoboa manage.py test modoboa.core modoboa.admin modoboa.limits modoboa.relaydomains
+  - coverage run --source ../modoboa manage.py test modoboa.core modoboa.lib modoboa.admin modoboa.limits modoboa.relaydomains
 
 after_success:
   - codecov
diff --git a/modoboa/core/commands/__init__.py b/modoboa/core/commands/__init__.py
index a45b85a9d..f21b36fa7 100644
--- a/modoboa/core/commands/__init__.py
+++ b/modoboa/core/commands/__init__.py
@@ -8,7 +8,7 @@ import sys
 
 from django.conf import settings
 from django.template import Context, Template
-from django.utils import six
+from django.utils.encoding import smart_str
 
 
 class Command(object):
@@ -66,12 +66,8 @@ def scan_for_commands(dirname=""):
         if os.path.isfile(f):
             continue
         cmdname = f.replace(".py", "")
-        if six.PY2:
-            fromlist = [cmdname.encode()]
-        else:
-            fromlist = [cmdname]
         cmdmod = __import__("modoboa.core.commands", globals(), locals(),
-                            fromlist)
+                            [smart_str(cmdname)])
         cmdmod = getattr(cmdmod, cmdname)
         if "_" in cmdname:
             cmdclassname = "".join(
diff --git a/modoboa/core/commands/deploy.py b/modoboa/core/commands/deploy.py
index 6f07ef462..5a21e4fbf 100644
--- a/modoboa/core/commands/deploy.py
+++ b/modoboa/core/commands/deploy.py
@@ -21,7 +21,7 @@ except ImportError:
 import django
 from django.core import management
 from django.template import Context, Template
-from django.utils import six
+from django.utils.encoding import smart_str
 import dj_database_url
 
 from modoboa.core.commands import Command
@@ -232,11 +232,9 @@ class DeployCommand(Command):
             os.path.join(os.path.dirname(__file__), "../../bower_components")
         )
 
-        if six.PY2:
-            fromlist = ['settings'.encode()]
-        else:
-            fromlist = ['settings']
-        mod = __import__(parsed_args.name, globals(), locals(), fromlist)
+        mod = __import__(
+            parsed_args.name, globals(), locals(), [smart_str('settings')]
+        )
         tpl = self._render_template(
             "%s/settings.py.tpl" % self._templates_dir, {
                 'db_connections': connections,
diff --git a/modoboa/core/extensions.py b/modoboa/core/extensions.py
index 5b4732204..a6ea04909 100644
--- a/modoboa/core/extensions.py
+++ b/modoboa/core/extensions.py
@@ -4,7 +4,7 @@ from __future__ import unicode_literals
 
 from django.conf import settings
 from django.conf.urls import include, url
-from django.utils import six
+from django.utils.encoding import smart_str
 
 
 class ModoExtension(object):
@@ -79,11 +79,7 @@ class ExtensionsPool(object):
 
     def load_extension(self, name):
         """Load a registered extension."""
-        if six.PY2:
-            fromlist = ["modo_extension".encode()]
-        else:
-            fromlist = ["modo_extension"]
-        __import__(name, locals(), globals(), fromlist)
+        __import__(name, locals(), globals(), [smart_str('modo_extension')])
         extinstance = self.get_extension(name)
         if extinstance is None:
             return None
@@ -137,4 +133,5 @@ class ExtensionsPool(object):
             result += [infos]
         return sorted(result, key=lambda i: i["name"])
 
+
 exts_pool = ExtensionsPool()
diff --git a/modoboa/core/views/user.py b/modoboa/core/views/user.py
index dd01f270b..91acaff35 100644
--- a/modoboa/core/views/user.py
+++ b/modoboa/core/views/user.py
@@ -6,6 +6,7 @@ from django.shortcuts import render
 from django.template.loader import render_to_string
 from django.utils import translation
 from django.utils.translation import ugettext as _
+from django.utils.encoding import force_text
 
 from django.contrib.auth.decorators import login_required, user_passes_test
 
@@ -41,8 +42,9 @@ def profile(request, tplname='core/user_profile.html'):
         if form.is_valid():
             form.save()
             if update_password and form.cleaned_data["confirmation"] != "":
-                request.session["password"] = encrypt(
-                    form.cleaned_data["confirmation"])
+                request.session["password"] = force_text(encrypt(
+                    form.cleaned_data["confirmation"]
+                ))
             translation.activate(request.user.language)
             request.session[translation.LANGUAGE_SESSION_KEY] = (
                 request.user.language)
diff --git a/modoboa/lib/cryptutils.py b/modoboa/lib/cryptutils.py
index 16e8a82ca..717ef7f73 100644
--- a/modoboa/lib/cryptutils.py
+++ b/modoboa/lib/cryptutils.py
@@ -7,6 +7,8 @@ import base64
 import random
 import string
 
+from django.utils.encoding import force_bytes
+
 from Crypto.Cipher import AES
 
 from modoboa.parameters import tools as param_tools
@@ -32,7 +34,9 @@ def encrypt(clear):
     if type(clear) is str:
         clear = clear.encode("utf-8")
     if len(clear) % AES.block_size:
-        clear += " " * (AES.block_size - len(clear) % AES.block_size)
+        clear += (
+            force_bytes(" ") * (AES.block_size - len(clear) % AES.block_size)
+        )
     ciph = obj.encrypt(clear)
     ciph = base64.b64encode(ciph)
     return ciph
diff --git a/modoboa/lib/form_utils.py b/modoboa/lib/form_utils.py
index 31b6dc421..e2b7144b1 100644
--- a/modoboa/lib/form_utils.py
+++ b/modoboa/lib/form_utils.py
@@ -13,8 +13,7 @@ from django.forms.fields import Field
 from django.forms.widgets import RadioSelect
 from django.forms.widgets import RadioChoiceInput
 from django.shortcuts import render
-from django.utils import six
-from django.utils.encoding import force_text
+from django.utils.encoding import force_text, force_str
 from django.utils.html import conditional_escape
 from django.utils.safestring import mark_safe
 from django.utils.translation import ugettext as _, ugettext_lazy
@@ -22,11 +21,8 @@ from django.utils.translation import ugettext as _, ugettext_lazy
 from modoboa.lib.exceptions import BadRequest
 from modoboa.lib.web_utils import render_to_json_response
 
-if six.PY2:
-    meta_name = b"ABC"
-else:
-    meta_name = "ABC"
-ABC = abc.ABCMeta(meta_name, (object,), {})  # compatible with Python 2 *and* 3
+
+ABC = abc.ABCMeta(force_str('ABC'), (object,), {})
 
 
 class WizardStep(object):
diff --git a/modoboa/lib/ldap_utils.py b/modoboa/lib/ldap_utils.py
index 6ec1316fe..2952f0198 100644
--- a/modoboa/lib/ldap_utils.py
+++ b/modoboa/lib/ldap_utils.py
@@ -39,7 +39,7 @@ import ldap
 
 from django.conf import settings
 from django.utils.translation import ugettext as _
-from django.utils.encoding import smart_bytes
+from django.utils.encoding import force_bytes
 
 from modoboa.core.password_hashers import get_password_hasher
 from modoboa.lib.exceptions import InternalError
@@ -69,7 +69,7 @@ class LDAPAuthBackend(object):
 
     def _get_conn(self, dn, password):
         """Get a connection from the server."""
-        conn = ldap.initialize(self.server_uri)
+        conn = ldap.initialize(self.server_uri, bytes_mode=False)
         conn.set_option(ldap.OPT_X_TLS_DEMAND, True)
         conn.set_option(ldap.OPT_DEBUG_LEVEL, 255)
         conn.simple_bind_s(dn, password)
@@ -120,8 +120,8 @@ class LDAPAuthBackend(object):
                 ('"%s"' % newpassword).encode('utf-16').lstrip('\377\376')
             )
         ldif = [(ldap.MOD_REPLACE,
-                 smart_bytes(self.pwd_attr),
-                 smart_bytes(self._crypt_password(newpassword)))]
+                 self.pwd_attr,
+                 force_bytes(self._crypt_password(newpassword)))]
         try:
             self.conn.modify_s(user_dn, ldif)
         except ldap.LDAPError as e:
diff --git a/modoboa/limits/tests/test_api.py b/modoboa/limits/tests/test_api.py
index b13a2246f..d671c0c2c 100644
--- a/modoboa/limits/tests/test_api.py
+++ b/modoboa/limits/tests/test_api.py
@@ -103,7 +103,9 @@ class APIAdminLimitsTestCase(lib_tests.ModoAPITestCase):
         data["name"] = "test5.com"
         response = self.client.post(url, data, format="json")
         self.assertEqual(response.status_code, 403)
-        self.assertEqual(response.content, '"Domains: limit reached"')
+        self.assertEqual(
+            response.content.decode('utf-8'), '"Domains: limit reached"'
+        )
 
         self.client.delete(
             reverse("api:domain-detail",
diff --git a/modoboa/relaydomains/tests.py b/modoboa/relaydomains/tests.py
index 957a165c1..fe773212f 100644
--- a/modoboa/relaydomains/tests.py
+++ b/modoboa/relaydomains/tests.py
@@ -2,8 +2,6 @@
 
 from __future__ import unicode_literals
 
-import json
-
 from django.core.files.base import ContentFile
 from django.core.urlresolvers import reverse
 from django.test import TestCase
@@ -88,7 +86,7 @@ class RelayDomainsTestCase(ModoTestCase, Operations):
         url = reverse("admin:_domain_list")
         response = self.client.get(url)
         self.assertEqual(response.status_code, 200)
-        content = json.loads(response.content)
+        content = response.json()
         self.assertIn("relaydomain.tld", content["rows"])
         self.assertIn("Relay Domain", content["rows"])
 
diff --git a/tox.ini b/tox.ini
index 370af28f5..6d4ef5c08 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,7 @@ envlist = py27,py34
 changedir=test_project
 commands =
     python ../tests.py
-    coverage run --source modoboa manage.py test modoboa.core modoboa.lib modoboa.admin.tests modoboa.limits modoboa.relaydomains
+    coverage run --source modoboa manage.py test modoboa.core modoboa.lib modoboa.admin modoboa.limits modoboa.relaydomains
     coverage report --show-missing
 deps =
     -r{toxinidir}/test-requirements.txt