diff --git a/Transceiver52M/Transceiver.cpp b/Transceiver52M/Transceiver.cpp
index 17e0476..af6b0dd 100644
--- a/Transceiver52M/Transceiver.cpp
+++ b/Transceiver52M/Transceiver.cpp
@@ -1,6 +1,8 @@
 /*
 * Copyright 2008, 2009, 2010 Free Software Foundation, Inc.
 *
+* SPDX-License-Identifier: GPL-3.0+
+*
 * This software is distributed under the terms of the GNU Public License.
 * See the COPYING file in the main directory for details.
 *