diff --git a/.travis.yml b/.travis.yml
index 5988dc2..af7e5ab 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: python
 sudo: false
-python: 2.7
+python: 3.6
 env:
   matrix:
     - DJANGO='django~=1.8.0'
diff --git a/djcroco/fields.py b/djcroco/fields.py
index 075e6ec..6266148 100644
--- a/djcroco/fields.py
+++ b/djcroco/fields.py
@@ -95,8 +95,7 @@ def __str__(self):
         return "%s" % self.attrs['name']
 
 
-class CrocoField(models.Field):
-    __metaclass__ = models.SubfieldBase
+class CrocoField(models.Field, metaclass=models.SubfieldBase):
     description = _("CrocoField")
 
     def __init__(self, verbose_name=None, name=None, *args, **kwargs):
diff --git a/djcroco/templatetags/croco_tags.py b/djcroco/templatetags/croco_tags.py
index 5945ac6..5d63c1f 100644
--- a/djcroco/templatetags/croco_tags.py
+++ b/djcroco/templatetags/croco_tags.py
@@ -1,5 +1,4 @@
-import urllib
-import urlparse
+from urllib.parse import urlencode, urlparse, urlunparse
 
 from django import template
 
@@ -19,12 +18,12 @@ def add_query_params(url, params=None):
     if not params:
         return url
 
-    encoded = urllib.urlencode(params)
-    url = urlparse.urlparse(url)
+    encoded = urlencode(params)
+    url = urlparse(url)
     if url.query:
         encoded = url.query + '&' + encoded
 
-    return urlparse.urlunparse((
+    return urlunparse((
         url.scheme,
         url.netloc,
         url.path,
diff --git a/djcroco/tests/tests.py b/djcroco/tests/tests.py
index c512266..c74db51 100644
--- a/djcroco/tests/tests.py
+++ b/djcroco/tests/tests.py
@@ -30,7 +30,7 @@ def render(self, tmpl):
     def assertContains(self, test_value, expected_set):
         # That assert method does not exist in Py2.6
         msg = "%s does not contain %s" % (test_value, expected_set)
-        self.assert_(test_value not in expected_set, msg)
+        self.assertTrue(test_value not in expected_set, msg)
 
     def test_document_empty(self):
         # Ensure document can be empty
@@ -49,7 +49,7 @@ def test_document_name(self):
     def test_document_size(self):
         # Ensure correct size
         self.assertEqual(self.instance.document.size, 679)
-        self.assertEqual(self.instance.document.size_human, u'679\xa0bytes')
+        self.assertEqual(self.instance.document.size_human, '679\xa0bytes')
 
     def test_document_type(self):
         # Ensure correct file type