diff --git a/src/authentication/db-connection.js b/src/authentication/db-connection.js
index 61fbd24c..41843c80 100644
--- a/src/authentication/db-connection.js
+++ b/src/authentication/db-connection.js
@@ -33,6 +33,7 @@ function DBConnection(request, options) {
  * @param {String} [options.picture] A URI pointing to the user's picture.
  * @param {String} options.connection name of the connection where the user will be created
  * @param {Object} [options.user_metadata] additional signup attributes used for creating the user. Will be stored in `user_metadata`
+ * @param {String} [options.captcha] the attempted solution for the captcha, if one was presented
  * @param {signUpCallback} cb
  * @see   {@link https://auth0.com/docs/api/authentication#signup}
  * @ignore
diff --git a/src/web-auth/index.js b/src/web-auth/index.js
index 4733bddd..bd93f7c6 100644
--- a/src/web-auth/index.js
+++ b/src/web-auth/index.js
@@ -792,6 +792,7 @@ WebAuth.prototype.passwordlessStart = function (options, cb) {
  * @param {String} [options.name] The user's full name.
  * @param {String} [options.nickname] The user's nickname.
  * @param {String} [options.picture] A URI pointing to the user's picture.
+ * @param {String} [options.captcha] the attempted solution for the captcha, if one was presented
  * @param {signUpCallback} cb
  * @see   {@link https://auth0.com/docs/api/authentication#signup}
  * @memberof WebAuth.prototype