diff --git a/model_utils/tests/tests.py b/model_utils/tests/tests.py
index 78874d3..c5d175d 100644
--- a/model_utils/tests/tests.py
+++ b/model_utils/tests/tests.py
@@ -593,7 +593,7 @@ if introspector:
 
 
         def test_no_excerpt_field_works(self):
-            from models import NoRendered
+            from .models import NoRendered
             self.assertRaises(FieldDoesNotExist,
                               NoRendered._meta.get_field,
                               '_body_excerpt')
diff --git a/tox.ini b/tox.ini
index a94d144..6067c98 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,85 +1,109 @@
 [tox]
 envlist =
-    py26-1.4, py26-1.5, py26-trunk,
-    py27-1.4, py27-1.5, py27-trunk, py27-1.4-nosouth,
-    py32-1.5-nosouth, py32-trunk-nosouth,
-    py33-1.5-nosouth, py33-trunk-nosouth
+    py26-1.4, py26-1.5, py26-1.6,
+    py27-1.4, py27-1.5, py27-1.6, py27-trunk, py27-1.5-nosouth,
+    py32-1.5, py32-1.6, py32-trunk,
+    py33-1.5, py33-1.6, py33-trunk
 
 [testenv]
 deps =
-    South == 0.7.6
+    South == 0.8.1
     coverage == 3.6
 commands = coverage run -a setup.py test
 
 [testenv:py26-1.4]
 basepython = python2.6
 deps =
-    django == 1.4.5
+    Django == 1.4.5
     South == 0.7.6
     coverage == 3.6
 
 [testenv:py26-1.5]
 basepython = python2.6
 deps =
-    django == 1.5.1
-    South == 0.7.6
+    Django == 1.5.1
+    South == 0.8.1
     coverage == 3.6
 
-[testenv:py26-trunk]
+[testenv:py26-1.6]
 basepython = python2.6
 deps =
-    https://github.com/django/django/tarball/master
-    South == 0.7.6
+    https://github.com/django/django/tarball/stable/1.6.x
+    South == 0.8.1
     coverage == 3.6
 
 [testenv:py27-1.4]
 basepython = python2.7
 deps =
-    django == 1.4.5
-    South == 0.7.6
+    Django == 1.4.5
+    South == 0.8.1
     coverage == 3.6
 
 [testenv:py27-1.5]
 basepython = python2.7
 deps =
-    django == 1.5.1
-    South == 0.7.6
+    Django == 1.5.1
+    South == 0.8.1
+    coverage == 3.6
+
+[testenv:py27-1.6]
+basepython = python2.7
+deps =
+    https://github.com/django/django/tarball/stable/1.6.x
+    South == 0.8.1
     coverage == 3.6
 
 [testenv:py27-trunk]
 basepython = python2.7
 deps =
     https://github.com/django/django/tarball/master
-    South == 0.7.6
+    South == 0.8.1
     coverage == 3.6
 
-[testenv:py32-1.5-nosouth]
-basepython = python3.2
-deps =
-    django == 1.5.1
-    coverage == 3.6
-
-[testenv:py32-trunk-nosouth]
-basepython = python3.2
-deps =
-    https://github.com/django/django/tarball/master
-    coverage == 3.6
-
-[testenv:py33-1.5-nosouth]
-basepython = python3.3
-deps =
-    django == 1.5.1
-    coverage == 3.6
-
-[testenv:py33-trunk-nosouth]
-basepython = python3.3
-deps =
-    https://github.com/django/django/tarball/master
-    coverage == 3.6
-
-
-[testenv:py27-1.4-nosouth]
+[testenv:py27-1.5-nosouth]
 basepython = python2.7
 deps =
-    django == 1.4.5
+    Django == 1.5.1
+    coverage == 3.6
+
+[testenv:py32-1.5]
+basepython = python3.2
+deps =
+    Django == 1.5.1
+    South == 0.8.1
+    coverage == 3.6
+
+[testenv:py32-1.6]
+basepython = python3.2
+deps =
+    https://github.com/django/django/tarball/stable/1.6.x
+    South == 0.8.1
+    coverage == 3.6
+
+[testenv:py32-trunk]
+basepython = python3.2
+deps =
+    https://github.com/django/django/tarball/master
+    South == 0.8.1
+    coverage == 3.6
+
+[testenv:py33-1.5]
+basepython = python3.3
+deps =
+    Django == 1.5.1
+    South == 0.8.1
+    coverage == 3.6
+
+[testenv:py33-1.6]
+basepython = python3.3
+deps =
+    https://github.com/django/django/tarball/stable/1.6.x
+    South == 0.8.1
+    coverage == 3.6
+
+[testenv:py33-trunk]
+basepython = python3.3
+deps =
+    https://github.com/django/django/tarball/master
+    South == 0.8.1
     coverage == 3.6