1 files changed, 1 insertions, 0 deletions

diff --git a/tox.ini b/tox.ini
index 5821483..f2256c8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,6 +5,7 @@ envlist =
 
 [testenv]
 deps = flake8==3.6.0
+setenv = PYFLAKES_ERROR_UNKNOWN=1
 commands =
     python -m unittest discover pyflakes
     flake8 pyflakes setup.py