diff --git a/requirements.txt b/requirements.txt
index 9b29f12..4b4d9ef 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -6,7 +6,7 @@ pbr!=2.1.0,>=2.0.0 # Apache-2.0
 eventlet!=0.18.3,!=0.20.1,>=0.18.2 # MIT
 oslo.config>=5.2.0 # Apache-2.0
 oslo.log>=3.36.0 # Apache-2.0
-oslo.concurrency>=3.26.0 # Apache-2.0
+oslo.concurrency>=4.2.0 # Apache-2.0
 oslo.policy>=1.35.0 # Apache-2.0
 oslo.messaging>=6.3.0 # Apache-2.0
 oslo.db>=4.27.0 # Apache-2.0
diff --git a/test-requirements.txt b/test-requirements.txt
index 2d8ca9b..955ea7e 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -7,7 +7,7 @@ hacking>=0.10.2,<0.11  # Apache-2.0
 eventlet!=0.18.3,!=0.20.1,>=0.18.2 # MIT
 oslo.config>=5.2.0 # Apache-2.0
 oslo.log>=3.36.0 # Apache-2.0
-oslo.concurrency>=3.26.0 # Apache-2.0
+oslo.concurrency>=4.2.0 # Apache-2.0
 oslo.policy>=1.35.0 # Apache-2.0
 oslo.messaging>=6.3.0 # Apache-2.0
 oslo.db>=4.27.0 # Apache-2.0
diff --git a/tox.ini b/tox.ini
index 99020df..7952e99 100644
--- a/tox.ini
+++ b/tox.ini
@@ -23,12 +23,11 @@ basepython = python2.7
 commands = flake8 {posargs}
 
 [testenv:py35]
-basepython = python3.5
+basepython = python3
 
 
 [flake8]
 # TODO(dmllr): Analyze or fix the warnings blacklisted below
-# E711 comparison to None should be 'if cond is not None:'
 # E712 comparison to True should be 'if cond is True:' or 'if cond:'
 # H404 multi line docstring should start with a summary
 # H405 multi line docstring summary not separated with an empty line