diff --git a/tox.ini b/tox.ini
index 6d0332dd..a3dffb79 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,6 +5,8 @@ envlist = py35,py27,pep8
 
 [testenv]
 install_command = pip install {opts} {packages}
+whitelist_externals =
+  find
 setenv = OS_STDOUT_CAPTURE=1
          OS_STDERR_CAPTURE=1
          OS_TEST_TIMEOUT=60