diff --git a/auth0-js/auth0-js.d.ts b/auth0-js/auth0-js.d.ts
index f1b24653b4..ab76c4afa4 100644
--- a/auth0-js/auth0-js.d.ts
+++ b/auth0-js/auth0-js.d.ts
@@ -106,6 +106,7 @@ interface Auth0LoginOptions {
 
 interface Auth0SignupOptions extends Auth0LoginOptions {
     auto_login: boolean;
+    responseType: string;
 }
 
 interface Auth0Error {