diff --git a/mixins/view_support.js b/mixins/view_support.js
index 2f9eddd..42b5804 100644
--- a/mixins/view_support.js
+++ b/mixins/view_support.js
@@ -17,7 +17,7 @@ Flame.ViewSupport = {
         // Remove classNames up to Flame.View to make it easier to define custom
         // styles for buttons, checkboxes etc...
         // We only want to do this in the init of class that sets the flag
-        if (this.get('resetClassNames') && Object.getPrototypeOf) {
+        if (this.get('resetClassNames')) {
             var superClassNames = this._collectSuperClassNames();
             var classNames = this.get('classNames').removeObjects(superClassNames);
             this.set('classNames', classNames);
@@ -48,7 +48,10 @@ Flame.ViewSupport = {
     */
     _collectSuperClassNames: function() {
         var superClassNames = [];
-        var superClass = Object.getPrototypeOf(Object.getPrototypeOf(this));
+        var superClass = Object.getPrototypeOf(this);
+        // Find first superclass that doesn't have the resetClassNames property
+        while (superClass && superClass.resetClassNames && superClass.constructor !== Flame.View) superClass = Object.getPrototypeOf(superClass);
+        // Collect the classNames from super classes
         while (superClass && superClass.constructor !== Flame.View) {
             superClassNames.pushObjects(superClass.classNames || []);
             superClass = Object.getPrototypeOf(superClass);
diff --git a/views/lazy_tree_item_view.js b/views/lazy_tree_item_view.js
index 297fa86..62bd532 100644
--- a/views/lazy_tree_item_view.js
+++ b/views/lazy_tree_item_view.js
@@ -2,6 +2,7 @@
 
 Flame.LazyTreeItemView = Flame.LazyListItemView.extend({
     classNames: ['flame-tree-item-view'],
+    classNameBindings: ['isExpanded'],
     itemContent: '{{view.content}}',
     isExpanded: false,