diff --git a/app/src/components/Tree/TreeNode.tsx b/app/src/components/Tree/TreeNode.tsx
index 763984c..6fd08cf 100644
--- a/app/src/components/Tree/TreeNode.tsx
+++ b/app/src/components/Tree/TreeNode.tsx
@@ -98,7 +98,7 @@ class TreeNodeComponent extends React.Component<Props, State> {
   }
 
   private viewStateHasChanged = (msg: void) => {
-    this.setState({ selected: this.props.treeNode.viewModel!.isSelected() })
+    this.props.treeNode.viewModel && this.setState({ selected: this.props.treeNode.viewModel.isSelected() })
   }
 
   private removeSubscriber(treeNode: q.TreeNode<TopicViewModel>) {