diff --git a/tox.ini b/tox.ini
index ab712da..78fd079 100644
--- a/tox.ini
+++ b/tox.ini
@@ -29,7 +29,7 @@ deps =
     check-manifest
 commands =
     # flake8 src/tablib tests/
-    isort --check-only
+    isort --check-only --diff
     check-manifest -v
     python setup.py sdist
     twine check dist/*