diff --git a/src/fastTimeout.js b/src/fastTimeout.js
index 908e925..6659922 100644
--- a/src/fastTimeout.js
+++ b/src/fastTimeout.js
@@ -40,5 +40,6 @@ function enable() {
 }
 
 var hasSetImmediate = (typeof setImmediate === 'function');
+var hasPostMessage = (typeof self.postMessage === 'function');
 
-export default hasSetImmediate ? setImmediate : enable();
+export default hasPostMessage ? enable() : hasSetImmediate ? setImmediate : _.defer;