diff --git a/tox.ini b/tox.ini
index 4c2edbc..be122b4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,11 +9,10 @@
 [testenv]
 basepython = python3
 usedevelop = True
-install_command = pip install {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
    PYTHONWARNINGS=default::DeprecationWarning
-deps = -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+deps = -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
        -r{toxinidir}/test-requirements.txt
 commands = python setup.py test --slowest --testr-args='{posargs}'
 
@@ -25,8 +24,9 @@
 
 [flake8]
 # E123, E125 skipped as they are invalid PEP-8.
-
+# W503 line break before binary operator
+# W504 line break after binary operator
 show-source = True
-ignore = E123,E125
+ignore = E123,E125,W503,W504
 builtins = _
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build