diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 26cbe47576d6..a1f6c859fe89 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)kern_fork.c	8.6 (Berkeley) 4/8/94
- * $Id: kern_fork.c,v 1.50 1997/12/12 04:00:58 dyson Exp $
+ * $Id: kern_fork.c,v 1.51 1998/01/22 17:29:46 dyson Exp $
  */
 
 #include "opt_ktrace.h"
@@ -271,7 +271,8 @@ fork1(p1, flags)
 again:
 		for (; p2 != 0; p2 = p2->p_list.le_next) {
 			while (p2->p_pid == nextpid ||
-			    p2->p_pgrp->pg_id == nextpid) {
+			    p2->p_pgrp->pg_id == nextpid ||
+			    p2->p_session->s_sid == nextpid) {
 				nextpid++;
 				if (nextpid >= pidchecked)
 					goto retry;
@@ -281,6 +282,9 @@ fork1(p1, flags)
 			if (p2->p_pgrp->pg_id > nextpid &&
 			    pidchecked > p2->p_pgrp->pg_id)
 				pidchecked = p2->p_pgrp->pg_id;
+			if (p2->p_session->s_sid > nextpid &&
+			    pidchecked > p2->p_session->s_sid)
+				pidchecked = p2->p_session->s_sid;
 		}
 		if (!doingzomb) {
 			doingzomb = 1;
diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index e229a5d4cd4e..d546ad771911 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)kern_proc.c	8.7 (Berkeley) 2/14/95
- * $Id: kern_proc.c,v 1.36 1998/02/20 13:52:14 bde Exp $
+ * $Id: kern_proc.c,v 1.37 1998/07/11 07:45:40 bde Exp $
  */
 
 #include <sys/param.h>
@@ -223,6 +223,7 @@ enterpgrp(p, pgid, mksess)
 			MALLOC(sess, struct session *, sizeof(struct session),
 			    M_SESSION, M_WAITOK);
 			sess->s_leader = p;
+			sess->s_sid = p->p_pid;
 			sess->s_count = 1;
 			sess->s_ttyvp = NULL;
 			sess->s_ttyp = NULL;
diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c
index 24abb73f0ba6..59c01fb14bce 100644
--- a/sys/kern/kern_prot.c
+++ b/sys/kern/kern_prot.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)kern_prot.c	8.6 (Berkeley) 1/21/94
- * $Id: kern_prot.c,v 1.39 1997/12/20 03:05:46 sef Exp $
+ * $Id: kern_prot.c,v 1.40 1998/06/10 10:28:29 dfr Exp $
  */
 
 /*
@@ -151,7 +151,7 @@ getsid(p, uap)
 	if ((p == pfind(uap->pid)) == 0)
 		return ESRCH;
 found:
-	p->p_retval[0] = p->p_pgrp->pg_session->s_leader->p_pid;
+	p->p_retval[0] = p->p_session->s_sid;
 	return 0;
 }
 
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 2a7a7a39f5b2..635832291d02 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)proc.h	8.15 (Berkeley) 5/19/95
- * $Id: proc.h,v 1.57 1998/04/04 13:26:14 phk Exp $
+ * $Id: proc.h,v 1.58 1998/05/28 09:30:26 phk Exp $
  */
 
 #ifndef _SYS_PROC_H_
@@ -61,6 +61,7 @@ struct	session {
 	struct	proc *s_leader;		/* Session leader. */
 	struct	vnode *s_ttyvp;		/* Vnode of controlling terminal. */
 	struct	tty *s_ttyp;		/* Controlling terminal. */
+	pid_t	s_sid;			/* Session ID */
 	char	s_login[roundup(MAXLOGNAME, sizeof(long))];	/* Setlogin() name. */
 };