diff --git a/guides/ml-in-Wayang.md b/guides/ml-in-Wayang.md
index a985fadf4..dc6933378 100644
--- a/guides/ml-in-Wayang.md
+++ b/guides/ml-in-Wayang.md
@@ -1,3 +1,21 @@
+<!--
+
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+-->
 # Using Machine Learning for query optimization in Apache Wayang (incubating)
 Apache Wayang (incubating) can be customized with concrete
 implementations of the `EstimatableCost` interface in order to optimize