diff --git a/lower-constraints.txt b/lower-constraints.txt
index b2f74362..5bbce4b9 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -23,7 +23,7 @@ jsonpointer==1.13
 jsonschema==2.6.0
 keystoneauth1==3.4.0
 linecache2==1.0.0
-mccabe==0.2.1
+mccabe==0.6.0
 monotonic==0.6
 mox3==0.20.0
 msgpack-python==0.4.0
@@ -49,7 +49,7 @@ pep8==1.5.7
 prettytable==0.7.2
 pyasn1==0.1.8
 pycparser==2.18
-pyflakes==0.8.1
+pyflakes==2.1.0
 pyinotify==0.9.6
 pyparsing==2.1.0
 pyperclip==1.5.27
@@ -57,7 +57,7 @@ python-dateutil==2.5.3
 python-mimeparse==1.6.0
 python-subunit==1.0.0
 pytz==2013.6
-PyYAML==3.12
+PyYAML==3.13
 reno==3.1.0
 requests==2.14.2
 requests-mock==1.2.0
diff --git a/tox.ini b/tox.ini
index eda694dd..1e6c2523 100644
--- a/tox.ini
+++ b/tox.ini
@@ -100,6 +100,10 @@ builtins = _
 exclude = .venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,build,tools
 
 [testenv:lower-constraints]
+skip_install = True
+commands =
+  python -m pip install --no-deps -U .
+  stestr run {posargs}
 deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt