diff --git a/test-requirements.txt b/test-requirements.txt
index 7d9c2587..44b50231 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -10,7 +10,7 @@
 charm-tools>=2.4.4
 requests>=2.18.4
 mock>=1.2
-flake8>=2.2.4,<=2.4.1
+flake8>=2.2.4
 stestr>=2.2.0
 coverage>=4.5.2
 pyudev              # for ceph-* charm unit tests (need to fix the ceph-* charm unit tests/mocking)
diff --git a/tox.ini b/tox.ini
index b835733a..8080ba6d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -116,5 +116,5 @@ commands =
     functest-run-suite --keep-model --bundle {posargs}
 
 [flake8]
-ignore = E402,E226
+ignore = E402,E226,W504
 exclude = */charmhelpers