diff --git a/tox.ini b/tox.ini
index 57805db4..b39303f2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,6 +16,7 @@ setenv =
     NOSE_OPENSTACK_STDOUT=1
     NOSE_XUNIT=1
     DISCOVER_DIRECTORY=mistralclient/tests/unit
+    PYTHONWARNINGS=default::DeprecationWarning
 passenv = http_proxy HTTP_PROXY https_proxy HTTPS_PROXY no_proxy NO_PROXY
 deps =
     -r{toxinidir}/requirements.txt