diff --git a/tslib.es6.js b/tslib.es6.js
index f7c687f..e6d7777 100644
--- a/tslib.es6.js
+++ b/tslib.es6.js
@@ -107,7 +107,11 @@ export function __generator(thisArg, body) {
 
 export var __createBinding = Object.create ? (function(o, m, k, k2) {
     if (k2 === undefined) k2 = k;
-    Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } });
+    var desc = Object.getOwnPropertyDescriptor(m, k);
+    if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
+        desc = { enumerable: true, get: function() { return m[k]; } };
+    }
+    Object.defineProperty(o, k2, desc);
 }) : (function(o, m, k, k2) {
     if (k2 === undefined) k2 = k;
     o[k2] = m[k];
diff --git a/tslib.js b/tslib.js
index 2e4326a..2b7885c 100644
--- a/tslib.js
+++ b/tslib.js
@@ -153,7 +153,11 @@ var __createBinding;
 
     __createBinding = Object.create ? (function(o, m, k, k2) {
         if (k2 === undefined) k2 = k;
-        Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } });
+        var desc = Object.getOwnPropertyDescriptor(m, k);
+        if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) {
+            desc = { enumerable: true, get: function() { return m[k]; } };
+        }
+        Object.defineProperty(o, k2, desc);
     }) : (function(o, m, k, k2) {
         if (k2 === undefined) k2 = k;
         o[k2] = m[k];