diff --git a/plugins/auth-backend/config.d.ts b/plugins/auth-backend/config.d.ts
index 25cd8d88ec..075c5e7942 100644
--- a/plugins/auth-backend/config.d.ts
+++ b/plugins/auth-backend/config.d.ts
@@ -191,5 +191,9 @@ export interface Config {
        */
       backstageTokenExpiration?: HumanDuration;
     };
+    /**
+     * Additional app origins to allow for authenticating
+     */
+    experimentalExtraAllowedOrigins?: string;
   };
 }