diff --git a/core/src/main/java/com/predic8/membrane/core/interceptor/xmlprotection/XMLProtectionException.java b/core/src/main/java/com/predic8/membrane/core/interceptor/xmlprotection/XMLProtectionException.java
index 66edf2efb..d5b2a7164 100644
--- a/core/src/main/java/com/predic8/membrane/core/interceptor/xmlprotection/XMLProtectionException.java
+++ b/core/src/main/java/com/predic8/membrane/core/interceptor/xmlprotection/XMLProtectionException.java
@@ -1,3 +1,17 @@
+/* Copyright 2023 predic8 GmbH, www.predic8.com
+
+   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. */
+
 package com.predic8.membrane.core.interceptor.xmlprotection;
 
 public class XMLProtectionException extends Exception {