diff --git a/bugdaystats.py b/bugdaystats.py
index 6d5af17..211fdd3 100755
--- a/bugdaystats.py
+++ b/bugdaystats.py
@@ -15,12 +15,14 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import simplejson as json
 import os
 import sys
 import time
-from jinja2 import Environment, FileSystemLoader
+
+from jinja2 import Environment
+from jinja2 import FileSystemLoader
 from launchpadlib.launchpad import Launchpad
+import simplejson as json
 
 
 def create_files(templatepath, outputpath, projects):
@@ -146,23 +148,23 @@ def update_stats(outputpath, project_name, rotation, daily=False):
 if __name__ == '__main__':
 
     if len(sys.argv) < 2:
-        print >> sys.stderr, "No directory supplied"
+        print("No directory supplied", file=sys.stderr)
 
     basepath = os.path.dirname(sys.argv[0])
     configpath = os.path.join(basepath, "config.js")
     templatepath = os.path.join(basepath, "templates")
     outputpath = sys.argv[1]
     if not os.path.isdir(outputpath):
-        print >> sys.stderr, '%s is not a directory' % outputpath
+        print('%s is not a directory' % outputpath, file=sys.stderr)
         sys.exit(1)
 
     if not os.path.isfile(configpath):
-        print >> sys.stderr, '%s does not contain config.js' % basepath
+        print('%s does not contain config.js' % basepath, file=sys.stderr)
         sys.exit(1)
 
     cachedir = os.path.expanduser("~/.launchpadlib/cache/")
     if not os.path.exists(cachedir):
-        os.makedirs(cachedir, 0700)
+        os.makedirs(cachedir, 0o0700)
 
     with open(configpath, 'r') as configfile:
         config = json.load(configfile)
diff --git a/setup.py b/setup.py
index d49c60a..881c817 100644
--- a/setup.py
+++ b/setup.py
@@ -14,7 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
 from setuptools import setup
 
 setup(
diff --git a/test-requirements.txt b/test-requirements.txt
new file mode 100644
index 0000000..b218ef5
--- /dev/null
+++ b/test-requirements.txt
@@ -0,0 +1,5 @@
+# The order of packages is significant, because pip processes them in the order
+# of appearance. Changing the order has an impact on the overall integration
+# process, which may cause wedges in the gate later.
+hacking>=4.0.0,<4.1.0 # Apache-2.0
+flake8-logging-format>=0.6.0 # Apache-2.0
diff --git a/tox.ini b/tox.ini
index f3e0fc3..404a87b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,13 +1,25 @@
 [tox]
-envlist = pyflakes, pep8, py27
+minversion = 3.18.0
+skipsdist = True
+envlist = pep8,py27
 
 [testenv]
-install_command = pip install --allow-external lazr.authentication --allow-insecure lazr.authentication -U {opts} {packages}
+basepython = python3
+usedevelop = True
+install_command=python -m pip install -c{env:TOX_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master} {opts} {packages}
 
-[testenv:pyflakes]
-deps = pyflakes
-commands = pyflakes bugdaystats.py
+deps = -r{toxinidir}/test-requirements.txt
 
 [testenv:pep8]
-deps = pep8==1.3.3
-commands = pep8 --ignore=E125 --repeat --show-source --exclude=.tox .
+commands =
+  flake8 {posargs} .
+
+[flake8]
+# The following checks are ignored on purpose.
+#
+# E125 unexpected spaces around keyword/parameter equals
+# reason: no improvement in readability
+ignore = E251
+exclude = .git,.venv,.tox,dist,tools,doc/ext,*egg,build
+max-complexity = 30
+import-order-style = pep8