diff --git a/tox.ini b/tox.ini
index 237df7c4e..ab36b6644 100644
--- a/tox.ini
+++ b/tox.ini
@@ -26,7 +26,7 @@ commands = python setup.py test --coverage --testr-args='{posargs}'
 commands = python setup.py build_sphinx
 
 [testenv:debug]
-commands = oslo_debug_helper {posargs}
+commands = oslo_debug_helper -t bifrost/tests {posargs}
 
 [testenv:releasenotes]
 commands = sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html