diff --git a/tox.ini b/tox.ini
index a22db72..2ca724a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -15,6 +15,7 @@ deps =
   swh.core[http] >= 0.0.61
   .[testing]
   pytest-cov
+  ipdb
 commands =
   pytest {envsitepackagesdir}/swh/lister/ {posargs}