diff --git a/examples/dev.html b/examples/dev.html
index f4a855b3d..7a11279b2 100644
--- a/examples/dev.html
+++ b/examples/dev.html
@@ -34,8 +34,8 @@
                                 text: 1
                             }, {
                                 type: "bi.label",
-                                key: "2",
-                                text: 2
+                                key: "123",
+                                text: "start"
                             }])
                         }
                     }, {
diff --git a/src/core/wrapper/layout.js b/src/core/wrapper/layout.js
index 6f1824b5d..d6634e328 100644
--- a/src/core/wrapper/layout.js
+++ b/src/core/wrapper/layout.js
@@ -486,6 +486,7 @@ BI.Layout = BI.inherit(BI.Widget, {
         function addNode (vnode, index) {
             var opt = self._getOptions(vnode);
             var key = opt.key == null ? index : opt.key;
+            delete self._children[self._getChildName(index)];
             return children[key] = self._addElement(index, vnode);
         }