diff --git a/dist/index.js b/dist/index.js
index d28dfea..da16c93 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -66,7 +66,7 @@ function initialize() {
 exports.initialize = initialize;
 function createBrowserGlobals() {
     Object.getOwnPropertyNames(aurelia_pal_1.PLATFORM.global)
-        .filter(prop => typeof global[prop] === 'undefined')
+        .filter(prop => typeof global[prop] === 'undefined' && prop !== 'undefined')
         .forEach(prop => global[prop] = aurelia_pal_1.PLATFORM.global[prop]);
 }
 function globalize() {
diff --git a/src/index.ts b/src/index.ts
index 1c59f99..b82bf78 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -75,7 +75,7 @@ export function initialize(): void {
 function createBrowserGlobals() {
   Object.getOwnPropertyNames(PLATFORM.global)
     // avoid conflict with nodejs globals
-    .filter(prop => typeof global[prop] === 'undefined')
+    .filter(prop => typeof global[prop] === 'undefined' && prop !== 'undefined')
     .forEach(prop => global[prop] = PLATFORM.global[prop]);
 }