diff --git a/doc/playground.md b/doc/playground.md
index ccc5270db0..2ee2ee9db4 100644
--- a/doc/playground.md
+++ b/doc/playground.md
@@ -44,7 +44,7 @@ equivalent to:
 
 ```javascript
 var obj = {};
-if (Object.prototype.hasOwnProperty.call(obj, "x")) obj.x = 2;
+if (!Object.prototype.hasOwnProperty.call(obj, "x")) obj.x = 2;
 ```
 
 ### Method binding expression