diff --git a/tox.ini b/tox.ini
index 68b889e29..402ae8318 100644
--- a/tox.ini
+++ b/tox.ini
@@ -30,8 +30,7 @@ commands = python setup.py build_sphinx
 
 [flake8]
 # E123, E125 skipped as they are invalid PEP-8
-# H904  Wrap long lines in parentheses instead of a backslash
-ignore = E123,E125,H904
+ignore = E123,E125
 show-source = true
 builtins = _
 exclude=.venv*,.git,.tox,dist,doc,*lib/python*,*egg,tools,build