diff --git a/tox.ini b/tox.ini
index 645e24185..d3c8e753e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -35,7 +35,7 @@ commands =
     python setup.py build_sphinx
 
 [testenv:debug]
-commands = oslo_debug_helper {posargs}
+commands = oslo_debug_helper -t watcher/tests {posargs}
 
 [testenv:config]
 sitepackages = False