diff --git a/tox.ini b/tox.ini
index 6ec0b2c..4ffe721 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,6 +9,8 @@
          PYTHONHASHSEED=0
 usedevelop = True
 install_command = pip install -U {opts} {packages}
+whitelist_externals = bash
+
 
 [testenv:py26]
 setenv = OS_TEST_PATH=./tempest/tests