diff --git a/roles/preseed/molecule/default/tests/test_parameters_optional.py b/roles/preseed/molecule/default/tests/test_parameters_optional.py
index 0506f6387f6728b0ea5f8375217f1b1719969ce6..a781302ad539983bf2b2e39d16e52cc3696287d8 100644
--- a/roles/preseed/molecule/default/tests/test_parameters_optional.py
+++ b/roles/preseed/molecule/default/tests/test_parameters_optional.py
@@ -48,7 +48,7 @@ def test_preseed_configuration_file_content(host):
 
     with host.sudo():
         preseed_file = host.file(os.path.join(PRESEED_DIRECTORY, "%s.cfg" % hostname))
-        preseed_file_content = preseed_file.content_string
+        preseed_file_content = preseed_file.content_string_string
         ssh_public_key = "CUSTOMKEY"
 
     assert "d-i debian-installer/language string sr" in preseed_file_content