diff --git a/tox.ini b/tox.ini
index b5c9956..ffd9259 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,17 +1,25 @@
 [tox]
 envlist=flake8,py3
 
 [testenv:py3]
 deps =
   .[testing]
   pytest-cov
 commands =
   pytest --cov={envsitepackagesdir}/swh/loader/ --cov-branch \
          {envsitepackagesdir}/swh/loader/ {posargs}
 
+[testenv:py3-dev]
+deps =
+  .[testing]
+  pytest-cov
+  ipdb
+commands =
+  pytest {envsitepackagesdir}/swh/loader/ {posargs}
+
 [testenv:flake8]
 skip_install = true
 deps =
   flake8
 commands =
   {envpython} -m flake8