diff --git a/content/docs/addons-animation.md b/content/docs/addons-animation.md
index f83dd63f..fd724dbe 100644
--- a/content/docs/addons-animation.md
+++ b/content/docs/addons-animation.md
@@ -50,7 +50,7 @@ class TodoList extends React.Component {
 
   render() {
     const items = this.state.items.map((item, i) => (
-      <div key={item} onClick={() => this.handleRemove(i)}>
+      <div key={i} onClick={() => this.handleRemove(i)}>
         {item}
       </div>
     ));