diff --git a/sys/fs/procfs/procfs_vnops.c b/sys/fs/procfs/procfs_vnops.c
index b7e522bdaa2..b8bd8e97a22 100644
--- a/sys/fs/procfs/procfs_vnops.c
+++ b/sys/fs/procfs/procfs_vnops.c
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs_vnops.c	8.18 (Berkeley) 5/21/95
  *
- *	$Id: procfs_vnops.c,v 1.49 1997/12/20 03:05:47 sef Exp $
+ *	$Id: procfs_vnops.c,v 1.50 1997/12/27 02:56:25 bde Exp $
  */
 
 /*
@@ -236,6 +236,9 @@ procfs_ioctl(ap)
 		return ENOTTY;
 	}
 
+	if (!CHECKIO(p, procp))
+		return EPERM;
+
 	switch (ap->a_command) {
 	case PIOCBIS:
 	  procp->p_stops |= *(unsigned int*)ap->a_data;
diff --git a/sys/miscfs/procfs/procfs_vnops.c b/sys/miscfs/procfs/procfs_vnops.c
index b7e522bdaa2..b8bd8e97a22 100644
--- a/sys/miscfs/procfs/procfs_vnops.c
+++ b/sys/miscfs/procfs/procfs_vnops.c
@@ -36,7 +36,7 @@
  *
  *	@(#)procfs_vnops.c	8.18 (Berkeley) 5/21/95
  *
- *	$Id: procfs_vnops.c,v 1.49 1997/12/20 03:05:47 sef Exp $
+ *	$Id: procfs_vnops.c,v 1.50 1997/12/27 02:56:25 bde Exp $
  */
 
 /*
@@ -236,6 +236,9 @@ procfs_ioctl(ap)
 		return ENOTTY;
 	}
 
+	if (!CHECKIO(p, procp))
+		return EPERM;
+
 	switch (ap->a_command) {
 	case PIOCBIS:
 	  procp->p_stops |= *(unsigned int*)ap->a_data;