diff --git a/README.md b/README.md
index b1a0a81..1f9c5b5 100644
--- a/README.md
+++ b/README.md
@@ -72,7 +72,7 @@ const treeNodes = [
 const getNodeData = (node, nestingLevel) => ({
   data: {
     id: node.id.toString(), // mandatory
-    isLeaf: node.children.length === 0,
+    isLeaf: !!node.children,
     isOpenByDefault: true, // mandatory
     name: node.name,
     nestingLevel,
@@ -95,6 +95,8 @@ function* treeWalker() {
     // the `getNodeData` function constructed, so you can read any data from it.
     const parent = yield;
 
+    if (!parent.node.children) continue
+
     for (let i = 0; i < parent.node.children.length; i++) {
       // Step [3]: Yielding all the children of the provided component. Then we
       // will return for the step [2] with the first children.