diff --git a/tox.ini b/tox.ini
index 6d75cde5b..29d316620 100644
--- a/tox.ini
+++ b/tox.ini
@@ -162,7 +162,8 @@ deps =
     flake8-tidy-imports==1.0.0
     flake8-future-import==0.3.2
     hacking==0.11.0
-    pep257==0.7.0  # still needed by flake8-docstrings but ignored
+    # still needed by flake8-docstrings but ignored
+    pep257==0.7.0
     pydocstyle==1.0.0
 commands =
     {envpython} -m flake8