diff --git a/lib/6to5/transformation/transformers/es6/block-scoping.js b/lib/6to5/transformation/transformers/es6/block-scoping.js
index ebcd994a99..ea6d245aab 100644
--- a/lib/6to5/transformation/transformers/es6/block-scoping.js
+++ b/lib/6to5/transformation/transformers/es6/block-scoping.js
@@ -1,6 +1,7 @@
 "use strict";
 
 var traverse = require("../../../traverse");
+var object   = require("../../../helpers/object");
 var util     = require("../../../util");
 var t        = require("../../../types");
 var _        = require("lodash");
@@ -12,9 +13,10 @@ var isLet = function (node, parent) {
 
   // https://github.com/6to5/6to5/issues/255
   if (!t.isFor(parent) || t.isFor(parent) && parent.left !== node) {
-    _.each(node.declarations, function (declar) {
+    for (var i = 0; i < node.declarations.length; i++) {
+      var declar = node.declarations[i];
       declar.init = declar.init || t.identifier("undefined");
-    });
+    }
   }
 
   node._let = true;
@@ -82,9 +84,9 @@ function LetScoping(loopParent, block, parent, scope, file) {
   this.block      = block;
   this.file       = file;
 
-  this.outsideLetReferences = util.object();
+  this.outsideLetReferences = object();
   this.hasLetReferences     = false;
-  this.letReferences        = block._letReferences = util.object();
+  this.letReferences        = block._letReferences = object();
   this.body                 = [];
 }
 
@@ -150,7 +152,7 @@ LetScoping.prototype.remap = function () {
   // we have to check if any of our let variables collide with
   // those in upper scopes and then if they do, generate a uid
   // for them and replace all references with it
-  var remaps = util.object();
+  var remaps = object();
 
   for (var key in letRefs) {
     // just an Identifier node we collected in `getLetReferences`
diff --git a/lib/6to5/traverse/global-keys.json b/lib/6to5/traverse/global-keys.json
new file mode 100644
index 0000000000..f616905fbd
--- /dev/null
+++ b/lib/6to5/traverse/global-keys.json
@@ -0,0 +1,62 @@
+[
+  "Set",
+  "Map",
+  "WeakMap",
+  "WeakSet",
+  "Proxy",
+  "Promise",
+  "Reflect",
+  "Symbol",
+  "System",
+  "__filename",
+  "__dirname",
+  "GLOBAL",
+  "global",
+  "module",
+  "require",
+  "Buffer",
+  "console",
+  "exports",
+  "process",
+  "setTimeout",
+  "clearTimeout",
+  "setInterval",
+  "clearInterval",
+  "setImmediate",
+  "clearImmediate",
+  "Array",
+  "Boolean",
+  "Date",
+  "decodeURI",
+  "decodeURIComponent",
+  "encodeURI",
+  "encodeURIComponent",
+  "Error",
+  "eval",
+  "EvalError",
+  "Function",
+  "hasOwnProperty",
+  "isFinite",
+  "isNaN",
+  "JSON",
+  "Map",
+  "Math",
+  "Number",
+  "Object",
+  "Proxy",
+  "Promise",
+  "parseInt",
+  "parseFloat",
+  "RangeError",
+  "ReferenceError",
+  "RegExp",
+  "Set",
+  "String",
+  "SyntaxError",
+  "TypeError",
+  "URIError",
+  "WeakMap",
+  "WeakSet",
+  "arguments",
+  "NaN"
+]
diff --git a/lib/6to5/traverse/scope.js b/lib/6to5/traverse/scope.js
index 104511fbda..927c71f0e9 100644
--- a/lib/6to5/traverse/scope.js
+++ b/lib/6to5/traverse/scope.js
@@ -3,6 +3,7 @@
 module.exports = Scope;
 
 var traverse = require("./index");
+var object   = require("../helpers/object");
 var t        = require("../types");
 var _        = require("lodash");
 
@@ -28,14 +29,7 @@ function Scope(block, parent, file) {
   this.declarationKinds = info.declarationKinds;
 }
 
-var vars = require("jshint/src/vars");
-
-Scope.defaultDeclarations = _.flatten([
-  vars.newEcmaIdentifiers,
-  vars.node,
-  vars.ecmaIdentifiers,
-  vars.reservedVars
-].map(_.keys));
+Scope.defaultDeclarations = require("./global-keys");
 
 Scope.prototype._add = function (node, references, throwOnDuplicate) {
   if (!node) return;
@@ -190,8 +184,8 @@ Scope.prototype.getInfo = function () {
   if (block._scopeInfo) return block._scopeInfo;
 
   var info = block._scopeInfo = {};
-  var references = info.references = {};
-  var declarations = info.declarations = {};
+  var references = info.references = object();
+  var declarations = info.declarations = object();
   var declarationKinds = info.declarationKinds = {};
 
   var add = function (node, reference, throwOnDuplicate) {
@@ -199,7 +193,7 @@ Scope.prototype.getInfo = function () {
 
     if (!reference) {
       self._add(node, declarations, throwOnDuplicate);
-      self._add(node, declarationKinds[node.kind] = declarationKinds[node.kind] || {});
+      self._add(node, declarationKinds[node.kind] = declarationKinds[node.kind] || object());
     }
   };
 
@@ -323,7 +317,7 @@ Scope.prototype.getFunctionParent = function () {
  */
 
 Scope.prototype.getAllOfKind = function (kind) {
-  var ids = {};
+  var ids = object();
 
   var scope = this;
   do {
diff --git a/package.json b/package.json
index 686f16b957..203d362b55 100644
--- a/package.json
+++ b/package.json
@@ -42,7 +42,6 @@
     "esutils": "1.1.6",
     "esvalid": "1.1.0",
     "fs-readdir-recursive": "0.1.0",
-    "jshint": "2.5.11",
     "lodash": "2.4.1",
     "output-file-sync": "^1.1.0",
     "private": "0.1.6",
@@ -57,6 +56,7 @@
     "chai": "1.10.0",
     "istanbul": "0.3.5",
     "jscs": "^1.10.0",
+    "jshint": "2.5.11",
     "jshint-stylish": "1.0.0",
     "matcha": "0.6.0",
     "mocha": "2.1.0",