diff --git a/lib/6to5/transformation/transformers/es6-classes.js b/lib/6to5/transformation/transformers/es6-classes.js
index 01c1ee0729..063a91aaa4 100644
--- a/lib/6to5/transformation/transformers/es6-classes.js
+++ b/lib/6to5/transformation/transformers/es6-classes.js
@@ -141,10 +141,6 @@ Class.prototype.buildBody = function () {
   var staticProps;
 
   if (this.hasInstanceMutators) {
-    var protoId = util.template("prototype-identifier", {
-      CLASS_NAME: className
-    });
-
     instanceProps = util.buildDefineProperties(this.instanceMutatorMap, true);
   }
 
diff --git a/lib/6to5/transformation/transformers/es6-property-method-assignment.js b/lib/6to5/transformation/transformers/es6-property-method-assignment.js
index 00c4d0fa4b..b826f6977d 100644
--- a/lib/6to5/transformation/transformers/es6-property-method-assignment.js
+++ b/lib/6to5/transformation/transformers/es6-property-method-assignment.js
@@ -46,7 +46,7 @@ exports.Property = function (node, parent, file, scope) {
   }
 };
 
-exports.ObjectExpression = function (node, parent, file, scope) {
+exports.ObjectExpression = function (node) {
   var mutatorMap = {};
   var hasAny = false;