diff --git a/Makefile b/Makefile
index 1662412..c2bacc0 100755
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,5 @@
 #!/usr/bin/make -f
+# SPDX-License-Identifier: GPL-2.0
 # -*- makefile -*-
 #
 # Copyright (C) 2012-2017  B.A.T.M.A.N. contributors
diff --git a/alfred.h b/alfred.h
index df0bd9a..d12b47a 100644
--- a/alfred.h
+++ b/alfred.h
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/batadv_query.c b/batadv_query.c
index 387950a..ac29da1 100644
--- a/batadv_query.c
+++ b/batadv_query.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/batadv_query.h b/batadv_query.h
index 5633322..4bf30c2 100644
--- a/batadv_query.h
+++ b/batadv_query.h
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2006-2017  B.A.T.M.A.N. contributors:
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2006-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich, Marek Lindner
  *
diff --git a/batadv_querynl.c b/batadv_querynl.c
index c197d24..b58dac4 100644
--- a/batadv_querynl.c
+++ b/batadv_querynl.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2009-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2009-2017  B.A.T.M.A.N. contributors:
  *
  * Marek Lindner <mareklindner@neomailbox.ch>, Andrew Lunn <andrew@lunn.ch>
  *
diff --git a/batadv_querynl.h b/batadv_querynl.h
index 90f6546..8d76ea9 100644
--- a/batadv_querynl.h
+++ b/batadv_querynl.h
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2009-2017  B.A.T.M.A.N. contributors:
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2009-2017  B.A.T.M.A.N. contributors:
  *
  * Marek Lindner <mareklindner@neomailbox.ch>, Andrew Lunn <andrew@lunn.ch>
  *
diff --git a/batman_adv.h b/batman_adv.h
index efd641c..fb45338 100644
--- a/batman_adv.h
+++ b/batman_adv.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: ISC */
 /* Copyright (C) 2016-2017  B.A.T.M.A.N. contributors:
  *
  * Matthias Schiffer
diff --git a/bitops.h b/bitops.h
index 37ce7e8..459fafc 100644
--- a/bitops.h
+++ b/bitops.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: MIT */
 /* Minimal Linux-like bit manipulation helper functions
  * (reduced version for alfred)
  *
diff --git a/client.c b/client.c
index 27dbc4a..7c89f95 100644
--- a/client.c
+++ b/client.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/debugfs.c b/debugfs.c
index e90c3a8..1cea8ac 100644
--- a/debugfs.c
+++ b/debugfs.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2009 Clark Williams <williams@redhat.com>
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2009 Clark Williams <williams@redhat.com>
  * Copyright (C) 2009 Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
  *
  * This program is free software; you can redistribute it and/or
diff --git a/debugfs.h b/debugfs.h
index 5404a45..6e49efa 100644
--- a/debugfs.h
+++ b/debugfs.h
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2009 Clark Williams <williams@redhat.com>
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2009 Clark Williams <williams@redhat.com>
  * Copyright (C) 2009 Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
  *
  * This program is free software; you can redistribute it and/or
diff --git a/gpsd/Makefile b/gpsd/Makefile
index dae2b48..e3c824b 100755
--- a/gpsd/Makefile
+++ b/gpsd/Makefile
@@ -1,4 +1,5 @@
 #!/usr/bin/make -f
+# SPDX-License-Identifier: GPL-2.0
 # -*- makefile -*-
 #
 # Copyright (C) 2013-2017  B.A.T.M.A.N. contributors
diff --git a/gpsd/alfred-gpsd.c b/gpsd/alfred-gpsd.c
index 7147136..b2eee9b 100644
--- a/gpsd/alfred-gpsd.c
+++ b/gpsd/alfred-gpsd.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2013-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2013-2017  B.A.T.M.A.N. contributors:
  *
  * Andrew Lunn, Simon Wunderlich
  *
diff --git a/gpsd/alfred-gpsd.h b/gpsd/alfred-gpsd.h
index 0a3a31f..ce765c2 100644
--- a/gpsd/alfred-gpsd.h
+++ b/gpsd/alfred-gpsd.h
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2013-2017  B.A.T.M.A.N. contributors:
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2013-2017  B.A.T.M.A.N. contributors:
  *
  * Andrew Lunn, Simon Wunderlich
  *
diff --git a/hash.c b/hash.c
index ebdcb47..3ba5a5a 100644
--- a/hash.c
+++ b/hash.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2006-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2006-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich, Marek Lindner
  *
diff --git a/hash.h b/hash.h
index 3111b49..4ec5c57 100644
--- a/hash.h
+++ b/hash.h
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2006-2017  B.A.T.M.A.N. contributors:
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2006-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich, Marek Lindner
  *
diff --git a/list.h b/list.h
index 5d4c25a..f6c0cae 100644
--- a/list.h
+++ b/list.h
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 1991-2013 linux kernel contributors
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 1991-2013 linux kernel contributors
  *
  * Linus Torvalds, ...
  *
diff --git a/main.c b/main.c
index be79fb9..59a24c9 100644
--- a/main.c
+++ b/main.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/netlink.c b/netlink.c
index 7678f99..e050de3 100644
--- a/netlink.c
+++ b/netlink.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2009-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2009-2017  B.A.T.M.A.N. contributors:
  *
  * Marek Lindner <mareklindner@neomailbox.ch>, Andrew Lunn <andrew@lunn.ch>
  *
diff --git a/netlink.h b/netlink.h
index 446948c..81a8f8d 100644
--- a/netlink.h
+++ b/netlink.h
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2009-2017  B.A.T.M.A.N. contributors:
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2009-2017  B.A.T.M.A.N. contributors:
  *
  * Marek Lindner <mareklindner@neomailbox.ch>, Andrew Lunn <andrew@lunn.ch>
  *
diff --git a/netsock.c b/netsock.c
index ced8fbd..5de1bbb 100644
--- a/netsock.c
+++ b/netsock.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/packet.h b/packet.h
index a132326..a60c8ac 100644
--- a/packet.h
+++ b/packet.h
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich, Sven Eckelmann
  *
diff --git a/recv.c b/recv.c
index 0f8004e..b93af7c 100644
--- a/recv.c
+++ b/recv.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/send.c b/send.c
index 9c1e31b..f1be0ea 100644
--- a/send.c
+++ b/send.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/server.c b/server.c
index 199d38c..95e5f24 100644
--- a/server.c
+++ b/server.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/unix_sock.c b/unix_sock.c
index 7f5e99c..fd9465d 100644
--- a/unix_sock.c
+++ b/unix_sock.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/util.c b/util.c
index 87261a0..bf82d1e 100644
--- a/util.c
+++ b/util.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2012-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/vis/Makefile b/vis/Makefile
index 63500c9..18b8070 100755
--- a/vis/Makefile
+++ b/vis/Makefile
@@ -1,4 +1,5 @@
 #!/usr/bin/make -f
+# SPDX-License-Identifier: GPL-2.0
 # -*- makefile -*-
 #
 # Copyright (C) 2013-2017  B.A.T.M.A.N. contributors
diff --git a/vis/vis.c b/vis/vis.c
index 148c581..5371f05 100644
--- a/vis/vis.c
+++ b/vis/vis.c
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2013-2017  B.A.T.M.A.N. contributors:
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2013-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
diff --git a/vis/vis.h b/vis/vis.h
index b99e745..03028f0 100644
--- a/vis/vis.h
+++ b/vis/vis.h
@@ -1,5 +1,5 @@
-/*
- * Copyright (C) 2013-2017  B.A.T.M.A.N. contributors:
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2013-2017  B.A.T.M.A.N. contributors:
  *
  * Simon Wunderlich
  *
