diff --git a/setup.py b/setup.py
index 0cd6e76d3d..e0fc54660c 100755
--- a/setup.py
+++ b/setup.py
@@ -141,13 +141,13 @@ setup(name=name,
     license='GPL-3',
     python_requires='>=3.7',
     install_requires=requires,
+    extras_require={
+        'test': tests_require,
+        },
     dependency_links=dependency_links,
     zip_safe=False,
     entry_points="""
     [trytond.modules]
     account_tax_rule_country = trytond.modules.account_tax_rule_country
     """,
-    test_suite='tests',
-    test_loader='trytond.test_loader:Loader',
-    tests_require=tests_require,
     )
diff --git a/tests/__init__.py b/tests/__init__.py
index b4fb641568..4effdfa4a2 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -1,10 +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.account_tax_rule_country.tests.test_account_tax_rule_country import \
-        suite  # noqa: E501
-except ImportError:
-    from .test_account_tax_rule_country import suite
-
-__all__ = ['suite']
diff --git a/tests/test_account_tax_rule_country.py b/tests/test_module.py
similarity index 96%
rename from tests/test_account_tax_rule_country.py
rename to tests/test_module.py
index 9588ee1922..ca6a7decc9 100644
--- a/tests/test_account_tax_rule_country.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.modules.account.tests import create_chart
 from trytond.modules.company.tests import (
     CompanyTestMixin, create_company, set_company)
@@ -169,8 +167,4 @@ class AccountTaxRuleCountryTestCase(CompanyTestMixin, ModuleTestCase):
             self.assertListEqual(tax_rule.apply(tax, pattern), [tax.id])
 
 
-def suite():
-    suite = trytond.tests.test_tryton.suite()
-    suite.addTests(unittest.TestLoader().loadTestsFromTestCase(
-        AccountTaxRuleCountryTestCase))
-    return suite
+del ModuleTestCase
diff --git a/tox.ini b/tox.ini
index 3730339ea2..d99abdc928 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,8 +2,9 @@
 envlist = {py37,py38,py39,py310}-{sqlite,postgresql}
 
 [testenv]
+extras = test
 commands =
-    coverage run --include=.*/account_tax_rule_country/* setup.py test
+    coverage run --include=.*/account_tax_rule_country/* -m unittest discover -s tests
     coverage report --include=.*/account_tax_rule_country/* --omit=*/tests/*
 deps =
     coverage