diff --git a/docs/docs/09.1-animation.md b/docs/docs/09.1-animation.md
index fdcc40ae74..c3d6c23f5d 100644
--- a/docs/docs/09.1-animation.md
+++ b/docs/docs/09.1-animation.md
@@ -35,7 +35,7 @@ var TodoList = React.createClass({
   render: function() {
     var items = this.state.items.map(function(item, i) {
       return (
-        <div key={i} onClick={this.handleRemove.bind(this, i)}>
+        <div key={item} onClick={this.handleRemove.bind(this, i)}>
           {item}
         </div>
       );