diff --git a/tox.ini b/tox.ini
index d5e769764..df6387d5e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -14,7 +14,7 @@ DJANGO =
     master: djangomaster
 
 [testenv]
-commands = ./runtests.py --fast --coverage {posargs}
+commands = python -W error::DeprecationWarning -W error::PendingDeprecationWarning runtests.py --fast --coverage {posargs}
 envdir = {toxworkdir}/venvs/{envname}
 setenv =
        PYTHONDONTWRITEBYTECODE=1