diff --git a/lib/6to5/transformation/transformers/es6-spread.js b/lib/6to5/transformation/transformers/es6-spread.js
index 2f544fe989..5a7b031ce1 100644
--- a/lib/6to5/transformation/transformers/es6-spread.js
+++ b/lib/6to5/transformation/transformers/es6-spread.js
@@ -59,7 +59,7 @@ exports.CallExpression = function (node, parent, file, scope) {
   var args = node.arguments;
   if (!hasSpread(args)) return;
 
-  var contextLiteral = t.literal(null);
+  var contextLiteral = t.identifier("undefined");
 
   node.arguments = [];
 
@@ -99,7 +99,7 @@ exports.NewExpression = function (node, parent, file) {
   var args = node.arguments;
   if (!hasSpread(args)) return;
 
-  var nativeType = t.isIdentifier(node.callee) && _.contains(t.NATIVE_TYPES_NAMES, node.callee.name);
+  var nativeType = t.isIdentifier(node.callee) && _.contains(t.NATIVE_TYPE_NAMES, node.callee.name);
 
   var nodes = build(args, file);
 
diff --git a/lib/6to5/types/index.js b/lib/6to5/types/index.js
index efe141328f..e1f0b9ec90 100644
--- a/lib/6to5/types/index.js
+++ b/lib/6to5/types/index.js
@@ -3,7 +3,7 @@ var _       = require("lodash");
 
 var t = exports;
 
-t.NATIVE_TYPES_NAMES = ["Array", "Object", "Number", "Boolean", "Date", "Array", "String"];
+t.NATIVE_TYPE_NAMES = ["Array", "Object", "Number", "Boolean", "Date", "Array", "String"];
 
 //