diff --git a/tox.ini b/tox.ini
index 537b2f2..c436cdb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,9 +8,12 @@ usedevelop = True
 install_command = pip install -U {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
+whitelist_externals = find
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
-commands = ostestr {posargs}
+commands =
+         find . -type f -name "*.pyc" -delete
+         ostestr {posargs}
 
 [testenv:pep8]
 commands = flake8