diff --git a/L3-objects-and-classes/56-using-bind.js b/L3-objects-and-classes/56-using-bind.js
index bd309a0..d5bfba1 100644
--- a/L3-objects-and-classes/56-using-bind.js
+++ b/L3-objects-and-classes/56-using-bind.js
@@ -11,6 +11,7 @@ const dog = {
 };
 
 const myGrow = dog.growOneYear.bind(dog);
+invokeTwice(myGrow);
 
 dog.age;
 // 7