diff --git a/tox.ini b/tox.ini
index 130b32fe83..9d18cb4e73 100644
--- a/tox.ini
+++ b/tox.ini
@@ -73,7 +73,10 @@ commands =
     coverage report
 
 [testenv:debug]
-commands = oslo_debug_helper -t openstackclient/tests {posargs}
+passenv = OS_*
+commands =
+    pip install -q -U ipdb
+    oslo_debug_helper -t openstackclient/tests {posargs}
 
 [testenv:docs]
 commands = python setup.py build_sphinx