diff --git a/tox.ini b/tox.ini
index d627b630f2ce0540aa32626b1352955dff74cc47..b188089a09bf966be7a72fc2bd3577af9a3ca5ac 100644
--- a/tox.ini
+++ b/tox.ini
@@ -14,7 +14,8 @@ passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
           OS_STDOUT_CAPTURE OS_STDERR_CAPTURE OS_LOG_CAPTURE OS_TEST_TIMEOUT
           PYTHON OS_TEST_PATH LISTOPT IDOPTION
 commands =
-  find . -type f -name "*.pyc" -delete
+  find . -type f -name "*.py[c|o]" -delete
+  find . -type d -name "__pycache__" -delete
   python setup.py test --slowest --testr-args='{posargs}'
 
 [testenv:pep8]