diff --git a/odoo_openupgrade_wizard/tools/tools_system.py b/odoo_openupgrade_wizard/tools/tools_system.py
index b033c54..4f43de3 100644
--- a/odoo_openupgrade_wizard/tools/tools_system.py
+++ b/odoo_openupgrade_wizard/tools/tools_system.py
@@ -107,7 +107,7 @@ def get_local_user_id():
     return os.getuid()
 
 
-def execute_check_output(args_list, working_directory=False):
+def execute_check_output(args_list, working_directory=None):
     logger.debug(f"Execute {' '.join(args_list)}")
     subprocess.check_output(args_list, cwd=working_directory)