diff --git a/sys/netpfil/pf/if_pfsync.c b/sys/netpfil/pf/if_pfsync.c
index d6bdc25acf95..2c3930de225c 100644
--- a/sys/netpfil/pf/if_pfsync.c
+++ b/sys/netpfil/pf/if_pfsync.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD AND MIT
+ * SPDX-License-Identifier: (BSD-2-Clause-FreeBSD AND ISC)
  *
  * Copyright (c) 2002 Michael Shalayeff
  * Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.org>
diff --git a/sys/sparc64/pci/sbbc.c b/sys/sparc64/pci/sbbc.c
index 90ed258464ce..dd6b42841ef2 100644
--- a/sys/sparc64/pci/sbbc.c
+++ b/sys/sparc64/pci/sbbc.c
@@ -1,6 +1,6 @@
 /*	$OpenBSD: sbbc.c,v 1.7 2009/11/09 17:53:39 nicm Exp $	*/
 /*-
- * SPDX-License-Identifier: MIT AND BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: (ISC AND BSD-2-Clause-FreeBSD)
  *
  * Copyright (c) 2008 Mark Kettenis
  *
diff --git a/sys/sys/gpio.h b/sys/sys/gpio.h
index 0d8c3eb5b1d1..2505269de64d 100644
--- a/sys/sys/gpio.h
+++ b/sys/sys/gpio.h
@@ -1,7 +1,7 @@
 /* $NetBSD: gpio.h,v 1.7 2009/09/25 20:27:50 mbalmer Exp $ */
 /*	$OpenBSD: gpio.h,v 1.7 2008/11/26 14:51:20 mbalmer Exp $	*/
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD AND MIT
+ * SPDX-License-Identifier: (BSD-2-Clause-FreeBSD AND ISC)
  *
  * Copyright (c) 2009, Oleksandr Tymoshenko <gonzo@FreeBSD.org>
  * All rights reserved.
diff --git a/sys/sys/msg.h b/sys/sys/msg.h
index 36a5c8d8277f..5c9cdfe47d0c 100644
--- a/sys/sys/msg.h
+++ b/sys/sys/msg.h
@@ -4,7 +4,7 @@
 /*-
  * SVID compatible msg.h file
  *
- * SPDX-License-Identifier: MIT
+ * SPDX-License-Identifier: 0BSD
  *
  * Author:  Daniel Boulet
  *
diff --git a/sys/sys/snoop.h b/sys/sys/snoop.h
index 483cccf43b34..d999750df3ef 100644
--- a/sys/sys/snoop.h
+++ b/sys/sys/snoop.h
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: MIT
+ * SPDX-License-Identifier: 0BSD
  *
  * Copyright (c) 1995 Ugen J.S.Antsilevich
  *
diff --git a/sys/x86/isa/isa.c b/sys/x86/isa/isa.c
index e3edc0923425..7a98a2bf9ed8 100644
--- a/sys/x86/isa/isa.c
+++ b/sys/x86/isa/isa.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD AND MIT
+ * SPDX-License-Identifier: (BSD-2-Clause-FreeBSD AND ISC)
  *
  * Copyright (c) 1998 Doug Rabson
  * All rights reserved.
diff --git a/usr.bin/gencat/gencat.c b/usr.bin/gencat/gencat.c
index 323914ecee6f..2046a34a2f8c 100644
--- a/usr.bin/gencat/gencat.c
+++ b/usr.bin/gencat/gencat.c
@@ -4,7 +4,7 @@
 /*	$NetBSD: gencat.c,v 1.18 2003/10/27 00:12:43 lukem Exp $	*/
 
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-NetBSD AND MIT
+ * SPDX-License-Identifier: (BSD-2-Clause-NetBSD AND ISC)
  *
  * Copyright (c) 1996 The NetBSD Foundation, Inc.
  * All rights reserved.
diff --git a/usr.sbin/ppp/arp.c b/usr.sbin/ppp/arp.c
index 7c964e00bf04..b49515be70b7 100644
--- a/usr.sbin/ppp/arp.c
+++ b/usr.sbin/ppp/arp.c
@@ -2,7 +2,7 @@
  * sys-bsd.c - System-dependent procedures for setting up
  * PPP interfaces on bsd-4.4-ish systems (including 386BSD, NetBSD, etc.)
  *
- * SPDX-License-Identifier: MIT
+ * SPDX-License-Identifier: 0BSD
  *
  * Copyright (c) 1989 Carnegie Mellon University.
  * All rights reserved.
diff --git a/usr.sbin/watch/watch.c b/usr.sbin/watch/watch.c
index e6c6b230cfb2..afd59279ba8a 100644
--- a/usr.sbin/watch/watch.c
+++ b/usr.sbin/watch/watch.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: MIT
+ * SPDX-License-Identifier: 0BSD
  *
  * Copyright (c) 1995 Ugen J.S.Antsilevich
  *