diff --git a/tox.ini b/tox.ini
index 3d175eb..a7c6534 100644
--- a/tox.ini
+++ b/tox.ini
@@ -15,3 +15,6 @@ deps = -r{toxinidir}/test-requirements.txt
 [testenv:pep8]
 commands = flake8
 deps = flake8
+
+[flake8]
+max-line-length = 160