diff --git a/lib/utils.js b/lib/utils.js
index b062d8fd..a338d6e6 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -131,7 +131,15 @@ function isPlainObject(val) {
  * @return {boolean} True if value is a empty Object, otherwise false
  */
 function isEmptyObject(val) {
-  return val && Object.keys(val).length === 0 && Object.getPrototypeOf(val) === Object.prototype;
+  if (!isPlainObject(val)) {
+    return false;
+  }
+  for (var key in val) {
+    if (Object.prototype.hasOwnProperty.call(val, key)) {
+      return false;
+    }
+  }
+  return true;
 }
 
 /**