diff --git a/tests/scenario_marketing_automation.rst b/tests/scenario_marketing_automation.rst
index b529a37d94..1f005b3848 100644
--- a/tests/scenario_marketing_automation.rst
+++ b/tests/scenario_marketing_automation.rst
@@ -13,9 +13,10 @@ Imports::
 
 Patch sendmail_transactional::
 
-    >>> from unittest.mock import MagicMock
+    >>> from unittest.mock import patch
     >>> from trytond.modules.marketing_automation import marketing_automation
-    >>> marketing_automation.sendmail_transactional = smtp_calls = MagicMock()
+    >>> smtp_calls = patch.object(
+    ...     marketing_automation, 'sendmail_transactional').start()
 
 Activate modules::