diff --git a/sys/src/kern/boot/boot.c b/sys/src/kern/boot/boot.c
index 1f28da7..b1bc29d 100644
--- a/sys/src/kern/boot/boot.c
+++ b/sys/src/kern/boot/boot.c
@@ -4,6 +4,9 @@
 /* Portions of this file are Copyright (C) 2015-2018 Giacomo Tesio <giacomo@tesio.it>
  * See /doc/license/gpl-2.0.txt for details about the licensing.
  */
+/* Portions of this file are Copyright (C) 2015 Ronald G. Minnich <rminnich@gmail.com>
+ * See /doc/license/gpl-2.0.txt for details about the licensing.
+ */
 
 #include <u.h>
 #include <libc.h>
diff --git a/sys/src/kern/port/lib.h b/sys/src/kern/port/lib.h
index 073d554..bd179ec 100644
--- a/sys/src/kern/port/lib.h
+++ b/sys/src/kern/port/lib.h
@@ -1,3 +1,13 @@
+/* Copyright (C) Charles Forsyth
+ * See /doc/license/NOTICE.Plan9-9k.txt for details about the licensing.
+ */
+/* Portions of this file are Copyright (C) 2015-2018 Giacomo Tesio <giacomo@tesio.it>
+ * See /doc/license/gpl-2.0.txt for details about the licensing.
+ */
+/* Portions of this file are Copyright (C) 2015 Ronald G. Minnich <rminnich@gmail.com>
+ * See /doc/license/gpl-2.0.txt for details about the licensing.
+ */
+
 /*
  * functions (possibly) linked in, complete, from libc.
  */
diff --git a/sys/src/kern/port/sysfile.c b/sys/src/kern/port/sysfile.c
index ca63e04..00771ca 100644
--- a/sys/src/kern/port/sysfile.c
+++ b/sys/src/kern/port/sysfile.c
@@ -4,6 +4,9 @@
 /* Portions of this file are Copyright (C) 2015-2018 Giacomo Tesio <giacomo@tesio.it>
  * See /doc/license/gpl-2.0.txt for details about the licensing.
  */
+/* Portions of this file are Copyright (C) 2015 Ronald G. Minnich <rminnich@gmail.com>
+ * See /doc/license/gpl-2.0.txt for details about the licensing.
+ */
 #include	"u.h"
 #include	"../port/lib.h"
 #include	"mem.h"