diff --git a/src/pixi/core/Circle.js b/src/pixi/core/Circle.js
index a9ceed0..80148b1 100644
--- a/src/pixi/core/Circle.js
+++ b/src/pixi/core/Circle.js
@@ -69,5 +69,6 @@
     return (dx + dy <= r2);
 }
 
+// constructor
 PIXI.Circle.prototype.constructor = PIXI.Circle;