diff --git a/sys/kern/sched_4bsd.c b/sys/kern/sched_4bsd.c
index 399c9e51052..e4de5c99d53 100644
--- a/sys/kern/sched_4bsd.c
+++ b/sys/kern/sched_4bsd.c
@@ -53,6 +53,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/sysctl.h>
 #include <sys/sx.h>
 #include <sys/turnstile.h>
+#include <machine/pcb.h>
 #include <machine/smp.h>
 
 #ifdef HWPMC_HOOKS