diff --git a/tests/__init__.py b/tests/__init__.py
index 171049f..5256907 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -2,18 +2,3 @@
 # This file is part of the account-invoice-xrechnung-module
 # from m-ds for Tryton. The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
-
-import trytond.tests.test_tryton
-import unittest
-
-from .test_invoice import InvoiceTestCase
-
-
-__all__ = ['suite']
-
-
-def suite():
-    suite = trytond.tests.test_tryton.suite()
-    suite.addTests(unittest.TestLoader().loadTestsFromTestCase(
-        InvoiceTestCase))
-    return suite