diff --git a/roles/backup_server/molecule/default/tests/test_parameters_optional.py b/roles/backup_server/molecule/default/tests/test_parameters_optional.py
index 8da3ec26f8e67c435fade714a492c71090ebace3..0c8dc00f88233c4a6eef82e93fdce3b74b5e4a4d 100644
--- a/roles/backup_server/molecule/default/tests/test_parameters_optional.py
+++ b/roles/backup_server/molecule/default/tests/test_parameters_optional.py
@@ -4,7 +4,7 @@ import testinfra.utils.ansible_runner
 
 
 testinfra_hosts = testinfra.utils.ansible_runner.AnsibleRunner(
-    os.environ['MOLECULE_INVENTORY_FILE']).get_hosts(['parameters-optional'])
+    os.environ['MOLECULE_INVENTORY_FILE']).get_hosts('parameters-optional')
 
 
 def test_backup_client_users_and_groups(host):