diff --git a/setup.py b/setup.py
index 17e01fc3c8..0888b0b6f0 100755
--- a/setup.py
+++ b/setup.py
@@ -142,6 +142,4 @@ setup(name=name,
     [trytond.modules]
     carrier = trytond.modules.carrier
     """,
-    test_suite='tests',
-    test_loader='trytond.test_loader:Loader',
     )
diff --git a/tests/__init__.py b/tests/__init__.py
index 28f8675111..4effdfa4a2 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -1,9 +1,2 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
-
-try:
-    from trytond.modules.carrier.tests.test_carrier import suite
-except ImportError:
-    from .test_carrier import suite
-
-__all__ = ['suite']
diff --git a/tests/test_carrier.py b/tests/test_module.py
similarity index 56%
rename from tests/test_carrier.py
rename to tests/test_module.py
index 27158bd070..08f6a591ad 100644
--- a/tests/test_carrier.py
+++ b/tests/test_module.py
@@ -1,8 +1,6 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
-import unittest
 
-import trytond.tests.test_tryton
 from trytond.tests.test_tryton import ModuleTestCase
 
 
@@ -11,8 +9,4 @@ class CarrierTestCase(ModuleTestCase):
     module = 'carrier'
 
 
-def suite():
-    suite = trytond.tests.test_tryton.suite()
-    suite.addTests(unittest.TestLoader().loadTestsFromTestCase(
-            CarrierTestCase))
-    return suite
+del ModuleTestCase
diff --git a/tox.ini b/tox.ini
index b3f821335f..b1c4241558 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,7 +3,7 @@ envlist = {py37,py38,py39,py310}-{sqlite,postgresql}
 
 [testenv]
 commands =
-    coverage run --include=.*/carrier/* setup.py test
+    coverage run --include=.*/carrier/* -m unittest discover -s tests
     coverage report --include=.*/carrier/* --omit=*/tests/*
 deps =
     coverage