diff --git a/src/guide/reactivity.md b/src/guide/reactivity.md
index 679c03d557..4109899dab 100644
--- a/src/guide/reactivity.md
+++ b/src/guide/reactivity.md
@@ -146,7 +146,7 @@ var vm = new Vue({
     msg: 'hi'
   },
   computed: {
-    example: {
+    example: function () {
       return Date.now() + this.msg
     }
   }