diff --git a/lib/legacy/class.html b/lib/legacy/class.html
index 930015b757..17a21818ef 100644
--- a/lib/legacy/class.html
+++ b/lib/legacy/class.html
@@ -192,6 +192,7 @@
     /**
      * @param {!PolymerInit} info Polymer info object
      * @param {function(new:HTMLElement)} Base base class to extend with info object
+     * @param {Object} behaviors behaviors to copy into the element
      * @return {function(new:HTMLElement)} Generated class
      * @suppress {checkTypes}
      * @private
@@ -498,6 +499,8 @@
      *
      * @param {!PolymerInit} info Object containing Polymer metadata and functions
      *   to become class methods.
+     * @param {function(T):T} mixin Optional mixin to apply to legacy base class
+     *   before extending with Polymer metaprogramming.
      * @return {function(new:HTMLElement)} Generated class
      * @memberof Polymer
      */