diff --git a/tox.ini b/tox.ini
index 861074c..aaa2ca7 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,6 +4,7 @@ envlist =
     py34-django{18,19,110,111,200}
     py35-django{18,19,110,111,200,trunk}
     py36-django{111,200,trunk}
+    flake8
 
 [testenv]
 deps =
@@ -19,10 +20,18 @@ deps =
 ignore_outcome =
     djangotrunk: True
 passenv =
-  CI
-  TRAVIS
-  TRAVIS_*
+    CI
+    TRAVIS
+    TRAVIS_*
 
 commands =
     pip install -e .
     py.test {posargs}
+
+[testenv:flake8]
+basepython =
+    python3.6
+deps =
+    flake8
+commands =
+    flake8 model_utils tests