diff --git a/types/auth0-js/index.d.ts b/types/auth0-js/index.d.ts
index 31b97e528d..529ef1e512 100644
--- a/types/auth0-js/index.d.ts
+++ b/types/auth0-js/index.d.ts
@@ -738,6 +738,7 @@ export interface DbSignUpOptions {
     email: string;
     password: string;
     connection: string;
+    /** User desired username. Required if you use a database connection and you have enabled `Requires Username` */
     username?: string;
     scope?: string;
     user_metadata?: any;