diff --git a/lib/checkout.js b/lib/checkout.js
index 652f6116a..329e0c7f4 100644
--- a/lib/checkout.js
+++ b/lib/checkout.js
@@ -25,7 +25,7 @@ Checkout.head = function(url, options) {
 *
 * @async
 * @param {Repository} repo The repo to checkout an index
-* @param {Index} The index to checkout
+* @param {Index} index The index to checkout
 * @param {CheckoutOptions} [options] Options for the checkout
 * @return {Void} checkout complete
 */