diff --git a/lib/6to5/types.js b/lib/6to5/types.js
index c3ccde6d95..b1249068c3 100644
--- a/lib/6to5/types.js
+++ b/lib/6to5/types.js
@@ -48,7 +48,7 @@ exports.isReferenced = function (node, parent) {
 };
 
 exports.ensureBlock = function (node) {
-  node[key] = exports.toBlock(node.body, node);
+  node.body = exports.toBlock(node.body, node);
 };
 
 exports.toBlock = function (node, parent) {
@@ -84,6 +84,8 @@ exports.ensureExpressionType = function (node) {
 };
 
 exports.needsParans = function (node, parent) {
+  if (!parent) return false;
+
   //
   if (exports.isUnaryLike(node)) {
     return parent.type === "MemberExpression" && parent.object === node;
@@ -151,9 +153,18 @@ exports.needsParans = function (node, parent) {
         || parent.type === "YieldExpression";
   }
 
-  //if (parent.type === "NewExpression" && parent.callee === node) {
-  //  return containsCallExpression(node);
-  //}
+  if (parent.type === "NewExpression") {
+    if (node.type !== "Identifier" && node.callee === node) {
+      return true;
+    }
+  }
+
+  if (node.type === "NewExpression") {
+    // (new Foo).bar();
+    if (parent.type === "MemberExpression" && parent.object === node) {
+      return true;
+    }
+  }
 
   // (1).valueOf()
   if (node.type === "Literal" && _.isNumber(node.value) && parent.type === "MemberExpression" && parent.object === node) {