diff --git a/.gitignore b/.gitignore
index e63dffc..8699683 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@
 *.egg-info/
 *.egg/
 .coverage
+coverage.xml
 .project
 .idea/
 .pydevproject
diff --git a/.travis.yml b/.travis.yml
index 175a66b..5601d0a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,98 +10,98 @@ python:
   - "3.5"
   - "3.6"
 env:
-  - DJANGO="Django>=1.4,<1.5"
-  - DJANGO="Django>=1.5,<1.6"
-  - DJANGO="Django>=1.6,<1.7"
-  - DJANGO="Django>=1.7,<1.8"
-  - DJANGO="Django>=1.8,<1.9"
-  - DJANGO="Django>=1.9,<1.10"
-  - DJANGO="Django>=1.10,<1.11"
-  - DJANGO="Django>=1.11,<1.12"
-  - DJANGO="https://github.com/django/django/tarball/master"
+  - TOXENV="django14"
+  - TOXENV="django15"
+  - TOXENV="django16"
+  - TOXENV="django17"
+  - TOXENV="django18"
+  - TOXENV="django19"
+  - TOXENV="django110"
+  - TOXENV="django111"
+  - TOXENV="djangodev"
 
 matrix:
+  fast_finish: true
   exclude:
-  - python: "3.6"
-    env: DJANGO="Django>=1.4,<1.5"
-  - python: "3.6"
-    env: DJANGO="Django>=1.5,<1.6"
-  - python: "3.6"
-    env: DJANGO="Django>=1.6,<1.7"
-  - python: "3.6"
-    env: DJANGO="Django>=1.7,<1.8"
-  - python: "3.6"
-    env: DJANGO="Django>=1.8,<1.9"
-  - python: "3.6"
-    env: DJANGO="Django>=1.9,<1.10"
-  - python: "3.6"
-    env: DJANGO="Django>=1.10,<1.11"
+    - python: "3.6"
+      env: TOXENV="django14"
+    - python: "3.6"
+      env: TOXENV="django15"
+    - python: "3.6"
+      env: TOXENV="django16"
+    - python: "3.6"
+      env: TOXENV="django17"
+    - python: "3.6"
+      env: TOXENV="django18"
+    - python: "3.6"
+      env: TOXENV="django19"
+    - python: "3.6"
+      env: TOXENV="django110"
 
-  - python: "3.5"
-    env: DJANGO="Django>=1.4,<1.5"
-  - python: "3.5"
-    env: DJANGO="Django>=1.5,<1.6"
-  - python: "3.5"
-    env: DJANGO="Django>=1.6,<1.7"
-  - python: "3.5"
-    env: DJANGO="Django>=1.7,<1.8"
+    - python: "3.5"
+      env: TOXENV="django14"
+    - python: "3.5"
+      env: TOXENV="django15"
+    - python: "3.5"
+      env: TOXENV="django16"
+    - python: "3.5"
+      env: TOXENV="django17"
 
-  - python: "3.4"
-    env: DJANGO="Django>=1.4,<1.5"
-  - python: "3.4"
-    env: DJANGO="Django>=1.9,<1.10"
-  - python: "3.4"
-    env: DJANGO="Django>=1.10,<1.11"
-  - python: "3.4"
-    env: DJANGO="Django>=1.11,<1.12"
+    - python: "3.4"
+      env: TOXENV="django14"
+    - python: "3.4"
+      env: TOXENV="django19"
+    - python: "3.4"
+      env: TOXENV="django110"
+    - python: "3.4"
+      env: TOXENV="django111"
 
-  - python: "3.3"
-    env: DJANGO="Django>=1.4,<1.5"
-  - python: "3.3"
-    env: DJANGO="Django>=1.9,<1.10"
-  - python: "3.3"
-    env: DJANGO="Django>=1.10,<1.11"
-  - python: "3.3"
-    env: DJANGO="Django>=1.11,<1.12"
-  - python: "3.3"
-    env: DJANGO="https://github.com/django/django/tarball/master"
+    - python: "3.3"
+      env: TOXENV="django14"
+    - python: "3.3"
+      env: TOXENV="django19"
+    - python: "3.3"
+      env: TOXENV="django110"
+    - python: "3.3"
+      env: TOXENV="django111"
+    - python: "3.3"
+      env: TOXENV="djangodev"
 
-  - python: "3.2"
-    env: DJANGO="Django>=1.4,<1.5"
-  - python: "3.2"
-    env: DJANGO="Django>=1.9,<1.10"
-  - python: "3.2"
-    env: DJANGO="Django>=1.10,<1.11"
-  - python: "3.2"
-    env: DJANGO="Django>=1.11,<1.12"
-  - python: "3.2"
-    env: DJANGO="https://github.com/django/django/tarball/master"
+    - python: "3.2"
+      env: TOXENV="django14"
+    - python: "3.2"
+      env: TOXENV="django19"
+    - python: "3.2"
+      env: TOXENV="django110"
+    - python: "3.2"
+      env: TOXENV="django111"
+    - python: "3.2"
+      env: TOXENV="djangodev"
+
+    - python: "2.6"
+      env: TOXENV="django17"
+    - python: "2.6"
+      env: TOXENV="django18"
+    - python: "2.6"
+      env: TOXENV="django19"
+    - python: "2.6"
+      env: TOXENV="django110"
+    - python: "2.6"
+      env: TOXENV="django111"
+    - python: "2.6"
+      env: TOXENV="djangodev"
 
-  - python: "2.6"
-    env: DJANGO="Django>=1.7,<1.8"
-  - python: "2.6"
-    env: DJANGO="Django>=1.8,<1.9"
-  - python: "2.6"
-    env: DJANGO="Django>=1.9,<1.10"
-  - python: "2.6"
-    env: DJANGO="Django>=1.10,<1.11"
-  - python: "2.6"
-    env: DJANGO="Django>=1.11,<1.12"
-  - python: "2.6"
-    env: DJANGO="https://github.com/django/django/tarball/master"
   allow_failures:
-    - env: DJANGO="https://github.com/django/django/tarball/master"
+    - env: TOXENV="djangodev"
 
 before_install:
-- pip install codecov
-
-install:
-  - pip install -q $DJANGO coverage==3.6
+- pip install codecov coverage==3.6 tox
 
 script:
-  - coverage run --source=polymorphic runtests.py
+  - tox
 
 after_success:
+- coverage xml -i
 - codecov
 
 branches:
diff --git a/tox.ini b/tox.ini
index ee02b1b..cff1ea7 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,14 +5,13 @@ envlist=
     py32-django{15,16,17,18},
     py33-django{15,16,17,18},
     py34-django{15,16,17,18,19,110,111},
-    py35-django{18,19,110,111}
-    py35-django{18,19,110,111},
-    py36-django{111},
-    # py33-django-dev,
+    py35-django{18,19,110,111,dev},
+    py36-django{111,dev},
     docs,
 
 [testenv]
 deps =
+    coverage == 3.6
     django14: Django >= 1.4, < 1.5
     django15: Django >= 1.5, < 1.6
     django16: Django >= 1.6, < 1.7
@@ -21,9 +20,9 @@ deps =
     django19: Django >= 1.9, < 1.10
     django110: Django >= 1.10, < 1.11
     django111: Django >= 1.11, < 1.12
-    django-dev: https://github.com/django/django/tarball/master
+    djangodev: https://github.com/django/django/tarball/master
 commands=
-    python runtests.py
+    coverage run --source polymorphic runtests.py
 
 [testenv:docs]
 deps=Sphinx