diff --git a/tiny_gltf.h b/tiny_gltf.h
index f60d9fb..dccb1e0 100644
--- a/tiny_gltf.h
+++ b/tiny_gltf.h
@@ -3880,6 +3880,10 @@ static void SerializeGltfNode(Node &node, json &o) {
     SerializeNumberProperty<int>("camera", node.camera, o);
   }
 
+  if (node.extras.Type() != NULL_TYPE) {
+    SerializeValue("extras", node.extras, o);
+  }
+
   SerializeExtensionMap(node.extensions, o);
   SerializeStringProperty("name", node.name, o);
   SerializeNumberArrayProperty<int>("children", node.children, o);