diff --git a/src/v2/guide/list.md b/src/v2/guide/list.md
index 0abeec0a91..dfc90b7cc0 100644
--- a/src/v2/guide/list.md
+++ b/src/v2/guide/list.md
@@ -229,7 +229,8 @@ However, this won't automatically pass any data to the component, because compon
 <my-component
   v-for="(item, index) in items"
   v-bind:item="item"
-  v-bind:index="index">
+  v-bind:index="index"
+  v-bind:key="item.id">
 </my-component>
 ```