diff --git a/lib/6to5/scope.js b/lib/6to5/scope.js
index 8954f7eb0f..8cbcbf8cda 100644
--- a/lib/6to5/scope.js
+++ b/lib/6to5/scope.js
@@ -6,12 +6,15 @@ var _        = require("lodash");
 
 function Scope(parent, block) {
   this.parent = parent;
+  this.ids    = block._scopeIds = block._scopeIds || Scope.getIds(block);
+}
 
+Scope.getIds = function (block) {
   var ids = [];
 
   if (t.isBlockStatement(block)) {
     _.each(block.body, function (node) {
-      if (t.isVariableDeclaration(node)) {
+      if (t.isVariableDeclaration(node) && node.kind !== "var") {
         ids = ids.concat(t.getIds(node));
       }
     });
@@ -19,7 +22,7 @@ function Scope(parent, block) {
 
   if (t.isProgram(block) || t.isFunction(block)) {
     traverse(block, function (node) {
-      if (t.isVariableDeclaration(node)) {
+      if (t.isVariableDeclaration(node) && node.kind === "var") {
         ids = ids.concat(t.getIds(node));
       } else if (t.isFunction(node)) {
         return false;
@@ -33,12 +36,12 @@ function Scope(parent, block) {
     });
   }
 
-  this.ids = ids;
-}
+  return ids;
+};
 
-Scope.prototype.has = function (id) {
+Scope.prototype.has = function (id, noParent) {
   if (!id) return false;
   if (_.contains(this.ids, id)) return true;
-  if (this.parent) return this.parent.has(id);
+  if (noParent !== false && this.parent) return this.parent.has(id);
   return false;
 };