diff --git a/docs/10.1-animation.md b/docs/10.1-animation.md
index 74241251..dcea2d9e 100644
--- a/docs/10.1-animation.md
+++ b/docs/10.1-animation.md
@@ -29,7 +29,7 @@ var TodoList = React.createClass({
     this.setState({items: newItems});
   },
   handleRemove: function(i) {
-    var newItems = this.state.items;
+    var newItems = this.state.items.slice();
     newItems.splice(i, 1);
     this.setState({items: newItems});
   },