diff --git a/src/api/instance-methods.md b/src/api/instance-methods.md
index f1025401ea..86b5516010 100644
--- a/src/api/instance-methods.md
+++ b/src/api/instance-methods.md
@@ -158,7 +158,9 @@
   If you still want to call an unwatch function inside the callback, you should check its availability first:
 
   ```js
-  const unwatch = vm.$watch(
+  let unwatch = null
+  
+  unwatch = vm.$watch(
     'value',
     function() {
       doSomething()