diff --git a/index.js b/index.js
index aacf6ef..725692b 100644
--- a/index.js
+++ b/index.js
@@ -235,5 +235,5 @@ function isGeneratorFunction(obj) {
  */
 
 function isObject(val) {
-  return Object == val.constructor;
+  return (null !== val) && ('object' == typeof val);
 }