diff --git a/oslo_middleware/opts.py b/oslo_middleware/opts.py
index 1584f9b..6cf6f4d 100644
--- a/oslo_middleware/opts.py
+++ b/oslo_middleware/opts.py
@@ -132,7 +132,6 @@ def list_opts_cors():
     """
     return [
         ('cors', copy.deepcopy(cors.CORS_OPTS)),
-        ('cors.subdomain', copy.deepcopy(cors.CORS_OPTS))
     ]