diff --git a/device_simulator/bal_stub.c b/device_simulator/bal_stub.c
index b169e50..4b61bd5 100644
--- a/device_simulator/bal_stub.c
+++ b/device_simulator/bal_stub.c
@@ -1,3 +1,18 @@
+/*
+** Copyright 2017-present Open Networking Foundation
+**
+** Licensed 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.
+*/
 #ifdef BAL_STUB
 #include <stdlib.h>
 #include <stdio.h>