diff --git a/lemur/certificates/views.py b/lemur/certificates/views.py
index 18746636..a066f20f 100644
--- a/lemur/certificates/views.py
+++ b/lemur/certificates/views.py
@@ -1155,6 +1155,7 @@ class NotificationCertificatesList(AuthenticatedResource):
         )
         parser.add_argument("creator", type=str, location="args")
         parser.add_argument("show", type=str, location="args")
+        parser.add_argument("showExpired", type=int, location="args")
 
         args = parser.parse_args()
         args["notification_id"] = notification_id