diff --git a/tox.ini b/tox.ini
index eefe866d..50a300ef 100644
--- a/tox.ini
+++ b/tox.ini
@@ -72,7 +72,9 @@ exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 import_exceptions = zunclient._i18n
 
 [testenv:functional]
-commands = ostestr {posargs}
+commands = 
+    find . -type f -name "*.py[c|o]" -delete
+    ostestr {posargs}
 setenv =
   {[testenv]setenv}
   OS_TEST_PATH = ./zunclient/tests/functional/osc/v1