diff --git a/ironic_inspector/test/functional.py b/ironic_inspector/test/functional.py
index 17dfe8004..fc92aa5f0 100644
--- a/ironic_inspector/test/functional.py
+++ b/ironic_inspector/test/functional.py
@@ -171,7 +171,8 @@ def mocked_server():
         conf_file = os.path.join(d, 'test.conf')
         db_file = os.path.join(d, 'test.db')
         with open(conf_file, 'wb') as fp:
-            fp.write(CONF % {'db_file': db_file})
+            content = CONF % {'db_file': db_file}
+            fp.write(content.encode('utf-8'))
 
         with mock.patch.object(utils, 'check_auth'):
             with mock.patch.object(utils, 'get_client'):
diff --git a/tox.ini b/tox.ini
index 540caf82d..d1ad59f9d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -27,6 +27,11 @@ basepython = python2.7
 commands =
     python -m ironic_inspector.test.functional
 
+[testenv:func3]
+basepython = python3.4
+commands =
+    python3 -m ironic_inspector.test.functional
+
 [testenv:genconfig]
 envdir = {toxworkdir}/venv
 commands =