diff --git a/index.js b/index.js
index dcc4b41..b529a2e 100644
--- a/index.js
+++ b/index.js
@@ -148,8 +148,8 @@ function resolve(relative, base) {
  *
  * @constructor
  * @param {String} address URL we want to parse.
- * @param {Object|String} location Location defaults for relative paths.
- * @param {Boolean|Function} parser Parser for the query string.
+ * @param {Object|String} [location] Location defaults for relative paths.
+ * @param {Boolean|Function} [parser] Parser for the query string.
  * @private
  */
 function Url(address, location, parser) {