diff --git a/tox.ini b/tox.ini
--- a/tox.ini
+++ b/tox.ini
@@ -7,6 +7,7 @@
   testing
 deps =
   pytest-cov
+  dev: pdbpp
 setenv =
   SWH_KAFKA_ROOT = {env:SWH_KAFKA_ROOT:swh/journal/tests/kafka}
 commands =