diff --git a/share/man/man9/intr_event.9 b/share/man/man9/intr_event.9
index 8ca42892dd8f..3ae2d051074c 100644
--- a/share/man/man9/intr_event.9
+++ b/share/man/man9/intr_event.9
@@ -1,4 +1,10 @@
 .\" Copyright (c) 2001 John H. Baldwin <jhb@FreeBSD.org>
+.\" Copyright (c) 2006 Tom Rhodes <trhodes@FreeBSD.org>
+.\" Copyright (c) 2021 Mitchell Horne <mhorne@FreeBSD.org>
+.\" Copyright (c) 2022 The FreeBSD Foundation
+.\"
+.\" Portions of this documentation were written by Mitchell Horne
+.\" under sponsorship from the FreeBSD Foundation.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions