diff --git a/sys/arm64/include/profile.h b/sys/arm64/include/profile.h
index c2ec9b74325..087af0504c7 100644
--- a/sys/arm64/include/profile.h
+++ b/sys/arm64/include/profile.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
  * All rights reserved.
  *
diff --git a/sys/ddb/db_access.c b/sys/ddb/db_access.c
index ec2107352f1..4f8284525dd 100644
--- a/sys/ddb/db_access.c
+++ b/sys/ddb/db_access.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_access.h b/sys/ddb/db_access.h
index 2b8ac71bac1..ac11e92bf81 100644
--- a/sys/ddb/db_access.h
+++ b/sys/ddb/db_access.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_break.c b/sys/ddb/db_break.c
index c882584957c..6275f819a2b 100644
--- a/sys/ddb/db_break.c
+++ b/sys/ddb/db_break.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_break.h b/sys/ddb/db_break.h
index b35d7437781..2d3283cc152 100644
--- a/sys/ddb/db_break.h
+++ b/sys/ddb/db_break.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_capture.c b/sys/ddb/db_capture.c
index 056edef437c..678c0cd2f21 100644
--- a/sys/ddb/db_capture.c
+++ b/sys/ddb/db_capture.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
  *
  * Copyright (c) 2007 Robert N. M. Watson
diff --git a/sys/ddb/db_command.c b/sys/ddb/db_command.c
index effb5f0dfa2..a43305b6bbc 100644
--- a/sys/ddb/db_command.c
+++ b/sys/ddb/db_command.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_command.h b/sys/ddb/db_command.h
index 2103a02ae99..6178f6e274b 100644
--- a/sys/ddb/db_command.h
+++ b/sys/ddb/db_command.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_examine.c b/sys/ddb/db_examine.c
index a1e5a2858ab..fd100bd29ad 100644
--- a/sys/ddb/db_examine.c
+++ b/sys/ddb/db_examine.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_expr.c b/sys/ddb/db_expr.c
index 0b473735e3c..b3198611a04 100644
--- a/sys/ddb/db_expr.c
+++ b/sys/ddb/db_expr.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_input.c b/sys/ddb/db_input.c
index 04c0d592b8f..41396e0a041 100644
--- a/sys/ddb/db_input.c
+++ b/sys/ddb/db_input.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_lex.c b/sys/ddb/db_lex.c
index 4fdfa317c6e..8e25cc898fc 100644
--- a/sys/ddb/db_lex.c
+++ b/sys/ddb/db_lex.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_lex.h b/sys/ddb/db_lex.h
index e20907db842..e9ed3a66039 100644
--- a/sys/ddb/db_lex.h
+++ b/sys/ddb/db_lex.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_main.c b/sys/ddb/db_main.c
index da6a5130b4e..174f930fc7c 100644
--- a/sys/ddb/db_main.c
+++ b/sys/ddb/db_main.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_output.c b/sys/ddb/db_output.c
index c0dc58bc599..147a4c59778 100644
--- a/sys/ddb/db_output.c
+++ b/sys/ddb/db_output.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_output.h b/sys/ddb/db_output.h
index 795719fce6e..e64608bd66a 100644
--- a/sys/ddb/db_output.h
+++ b/sys/ddb/db_output.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_print.c b/sys/ddb/db_print.c
index e4efe0a560d..3ff0b781532 100644
--- a/sys/ddb/db_print.c
+++ b/sys/ddb/db_print.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_run.c b/sys/ddb/db_run.c
index 4ffba48583b..a55fcea9e63 100644
--- a/sys/ddb/db_run.c
+++ b/sys/ddb/db_run.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_sym.c b/sys/ddb/db_sym.c
index 8b257b19114..a2801398135 100644
--- a/sys/ddb/db_sym.c
+++ b/sys/ddb/db_sym.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_sym.h b/sys/ddb/db_sym.h
index 51744c50f4e..1ad35e2b0c8 100644
--- a/sys/ddb/db_sym.h
+++ b/sys/ddb/db_sym.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_variables.c b/sys/ddb/db_variables.c
index d69c9804ff5..2c3840339e4 100644
--- a/sys/ddb/db_variables.c
+++ b/sys/ddb/db_variables.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_variables.h b/sys/ddb/db_variables.h
index 1cbc481a1a7..bc7201e577b 100644
--- a/sys/ddb/db_variables.h
+++ b/sys/ddb/db_variables.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_watch.c b/sys/ddb/db_watch.c
index 23612fe5eb5..2a3ccbf8b00 100644
--- a/sys/ddb/db_watch.c
+++ b/sys/ddb/db_watch.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_watch.h b/sys/ddb/db_watch.h
index d4fdfc855bd..4757635d3da 100644
--- a/sys/ddb/db_watch.h
+++ b/sys/ddb/db_watch.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/ddb/db_write_cmd.c b/sys/ddb/db_write_cmd.c
index 2e0cf03c650..3b0102da5fc 100644
--- a/sys/ddb/db_write_cmd.c
+++ b/sys/ddb/db_write_cmd.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Mach Operating System
  * Copyright (c) 1991,1990 Carnegie Mellon University
  * All Rights Reserved.
diff --git a/sys/dev/fb/gfb.h b/sys/dev/fb/gfb.h
index ee70640b8a5..891d3172a55 100644
--- a/sys/dev/fb/gfb.h
+++ b/sys/dev/fb/gfb.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Copyright (c) 1995, 1996 Carnegie-Mellon University.
  * All rights reserved.
  *
diff --git a/sys/dev/mc146818/mc146818reg.h b/sys/dev/mc146818/mc146818reg.h
index 811187e4b7d..10071699882 100644
--- a/sys/dev/mc146818/mc146818reg.h
+++ b/sys/dev/mc146818/mc146818reg.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Copyright (c) 1995 Carnegie-Mellon University.
  * All rights reserved.
  *
diff --git a/sys/mips/include/cdefs.h b/sys/mips/include/cdefs.h
index 181d6ee618c..a7f118ea6a8 100644
--- a/sys/mips/include/cdefs.h
+++ b/sys/mips/include/cdefs.h
@@ -1,6 +1,8 @@
 /*	$NetBSD: cdefs.h,v 1.12 2006/08/27 19:04:30 matt Exp $	*/
 
-/*
+/*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Copyright (c) 1995 Carnegie-Mellon University.
  * All rights reserved.
  *
diff --git a/sys/mips/include/setjmp.h b/sys/mips/include/setjmp.h
index 920c942b0e5..8b6ca0478fd 100644
--- a/sys/mips/include/setjmp.h
+++ b/sys/mips/include/setjmp.h
@@ -1,6 +1,8 @@
 /* From: NetBSD: setjmp.h,v 1.2 1997/04/06 08:47:41 cgd Exp */
 
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Copyright (c) 1994, 1995 Carnegie-Mellon University.
  * All rights reserved.
  *
diff --git a/sys/powerpc/include/profile.h b/sys/powerpc/include/profile.h
index b1481a7a232..5f933551279 100644
--- a/sys/powerpc/include/profile.h
+++ b/sys/powerpc/include/profile.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
  * All rights reserved.
  *
diff --git a/sys/powerpc/powerpc/vm_machdep.c b/sys/powerpc/powerpc/vm_machdep.c
index cc9eea85a37..a34c657d9c0 100644
--- a/sys/powerpc/powerpc/vm_machdep.c
+++ b/sys/powerpc/powerpc/vm_machdep.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-4-Clause
+ * SPDX-License-Identifier: (BSD-4-Clause AND MIT-CMU)
  *
  * Copyright (c) 1982, 1986 The Regents of the University of California.
  * Copyright (c) 1989, 1990 William Jolitz
diff --git a/sys/riscv/include/profile.h b/sys/riscv/include/profile.h
index c2ec9b74325..087af0504c7 100644
--- a/sys/riscv/include/profile.h
+++ b/sys/riscv/include/profile.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
  * All rights reserved.
  *
diff --git a/sys/sparc64/include/profile.h b/sys/sparc64/include/profile.h
index 6c7d1b297ac..59cdec6b67c 100644
--- a/sys/sparc64/include/profile.h
+++ b/sys/sparc64/include/profile.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: MIT-CMU
+ *
  * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
  * All rights reserved.
  *
diff --git a/sys/vm/vm.h b/sys/vm/vm.h
index 5b1616c0eee..f674fc5626b 100644
--- a/sys/vm/vm.h
+++ b/sys/vm/vm.h
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_domain.c b/sys/vm/vm_domain.c
index a560d6fe803..9fe44168cfa 100644
--- a/sys/vm/vm_domain.c
+++ b/sys/vm/vm_domain.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
  * Copyright (c) 2015 Adrian Chadd <adrian@FreeBSD.org>.
  * All rights reserved.
  *
diff --git a/sys/vm/vm_domain.h b/sys/vm/vm_domain.h
index 1b8a3861963..3b99c43c910 100644
--- a/sys/vm/vm_domain.h
+++ b/sys/vm/vm_domain.h
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
  * Copyright (c) 2015 Adrian Chadd <adrian@FreeBSD.org>.
  * All rights reserved.
  *
diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index 1b03af4314d..ece496407c2 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-4-Clause
+ * SPDX-License-Identifier: (BSD-4-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_glue.c b/sys/vm/vm_glue.c
index 05a120dd610..a00272c2348 100644
--- a/sys/vm/vm_glue.c
+++ b/sys/vm/vm_glue.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_init.c b/sys/vm/vm_init.c
index d46c6060aa3..3d0b166bc48 100644
--- a/sys/vm/vm_init.c
+++ b/sys/vm/vm_init.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_kern.c b/sys/vm/vm_kern.c
index 2931f8085ca..333e38e2791 100644
--- a/sys/vm/vm_kern.c
+++ b/sys/vm/vm_kern.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_kern.h b/sys/vm/vm_kern.h
index b49aa524b32..20e847f5e5a 100644
--- a/sys/vm/vm_kern.h
+++ b/sys/vm/vm_kern.h
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 905ac1b9313..00dbc2d1bd0 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_map.h b/sys/vm/vm_map.h
index e4f93e4c8fd..0da693277b9 100644
--- a/sys/vm/vm_map.h
+++ b/sys/vm/vm_map.h
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index d1ba8b98925..f821150316f 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_object.h b/sys/vm/vm_object.h
index 4aa7ede1465..1edf2d59868 100644
--- a/sys/vm/vm_object.h
+++ b/sys/vm/vm_object.h
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 4f6dfbcdf0d..4711af9d16d 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991 Regents of the University of California.
  * All rights reserved.
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
index a4fec169e19..70aa20c056d 100644
--- a/sys/vm/vm_page.h
+++ b/sys/vm/vm_page.h
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_pageout.c b/sys/vm/vm_pageout.c
index 4ecae5ad5fd..81cab0e8cfb 100644
--- a/sys/vm/vm_pageout.c
+++ b/sys/vm/vm_pageout.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-4-Clause
+ * SPDX-License-Identifier: (BSD-4-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991 Regents of the University of California.
  * All rights reserved.
diff --git a/sys/vm/vm_pageout.h b/sys/vm/vm_pageout.h
index 75e3a147518..2cdb1492fab 100644
--- a/sys/vm/vm_pageout.h
+++ b/sys/vm/vm_pageout.h
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_pager.c b/sys/vm/vm_pager.c
index a9e1ffbc6ab..3864c9dfc1c 100644
--- a/sys/vm/vm_pager.c
+++ b/sys/vm/vm_pager.c
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_param.h b/sys/vm/vm_param.h
index 4ed7635de3a..308259cbc96 100644
--- a/sys/vm/vm_param.h
+++ b/sys/vm/vm_param.h
@@ -1,5 +1,5 @@
 /*-
- * SPDX-License-Identifier: BSD-3-Clause
+ * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
diff --git a/sys/vm/vm_swapout.c b/sys/vm/vm_swapout.c
index 726c2e2f91a..e3e8b8966d7 100644
--- a/sys/vm/vm_swapout.c
+++ b/sys/vm/vm_swapout.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: (BSD-4-Clause AND MIT-CMU)
+ *
  * Copyright (c) 1991 Regents of the University of California.
  * All rights reserved.
  * Copyright (c) 1994 John S. Dyson
diff --git a/sys/vm/vm_swapout_dummy.c b/sys/vm/vm_swapout_dummy.c
index 9cdfcb8ac95..4557a52c9ec 100644
--- a/sys/vm/vm_swapout_dummy.c
+++ b/sys/vm/vm_swapout_dummy.c
@@ -1,4 +1,6 @@
 /*-
+ * SPDX-License-Identifier: (BSD-4-Clause AND MIT-CMU)
+ *
  * Copyright (c) 1991 Regents of the University of California.
  * All rights reserved.
  * Copyright (c) 1994 John S. Dyson