diff --git a/modules/core/src/main/java/org/locationtech/jts/geom/ZInterpolating.java b/modules/core/src/main/java/org/locationtech/jts/geom/ZInterpolating.java
index 7c850787db..5c4ce08137 100644
--- a/modules/core/src/main/java/org/locationtech/jts/geom/ZInterpolating.java
+++ b/modules/core/src/main/java/org/locationtech/jts/geom/ZInterpolating.java
@@ -1,3 +1,15 @@
+/*
+ * Copyright (c) 2021 Björn Harrtell.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * and Eclipse Distribution License v. 1.0 which accompanies this distribution.
+ * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
+ * and the Eclipse Distribution License is available at
+ *
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ */
+
 package org.locationtech.jts.geom;
 
 /**