diff --git a/roles/mail_server/molecule/default/tests/test_optional.py b/roles/mail_server/molecule/default/tests/test_optional.py
index e7256af58e03c1515878bc2a1ce54a124e8442b1..15d96912ff00f2fc769c65358982d1fa8584890b 100644
--- a/roles/mail_server/molecule/default/tests/test_optional.py
+++ b/roles/mail_server/molecule/default/tests/test_optional.py
@@ -1,10 +1,11 @@
+import os
 import re
 
 import testinfra.utils.ansible_runner
 
 
 testinfra_hosts = testinfra.utils.ansible_runner.AnsibleRunner(
-    '.molecule/ansible_inventory.yml').get_hosts('parameters-optional')
+    os.environ['MOLECULE_INVENTORY_FILE']).get_hosts(['parameters-optional'])
 
 
 def test_smtp_tls_files(host):