diff --git a/tox.ini b/tox.ini
index 1eb5527..833cb66 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,24 +1,26 @@
 [tox]
 envlist=flake8,mypy,py3
 
 [testenv:py3]
 deps =
   .[testing]
   pytest-cov
 commands =
-  pytest --cov=swh --cov-branch {posargs}
+  pytest --cov={envsitepackagesdir}/swh/model \
+         {envsitepackagesdir}/swh/model \
+           --cov-branch {posargs}
 
 [testenv:flake8]
 skip_install = true
 deps =
   flake8
 commands =
   {envpython} -m flake8
 
 [testenv:mypy]
 skip_install = true
 deps =
   .[testing]
   mypy
 commands =
   mypy swh