Index: share/man/man9/style.9
===================================================================
--- share/man/man9/style.9
+++ share/man/man9/style.9
@@ -25,7 +25,7 @@
 .\"	From: @(#)style	1.14 (Berkeley) 4/28/95
 .\" $FreeBSD$
 .\"
-.Dd July 16, 2020
+.Dd October 28, 2020
 .Dt STYLE 9
 .Os
 .Sh NAME
@@ -156,9 +156,13 @@
 .In sys/types.h ;
 do not include both.
 .Pc
+Next
+.In sys/systm.h
+should be included.
 The remaining kernel headers should be sorted alphabetically.
 .Bd -literal
 #include <sys/types.h>	/* Non-local includes in angle brackets. */
+#include <sys/systm.h>
 #include <sys/endian.h>
 #include <sys/lock.h>
 #include <sys/queue.h>