diff --git a/sys/pc98/i386/machdep.c b/sys/pc98/i386/machdep.c
index f49cfac4e93e..970b01679857 100644
--- a/sys/pc98/i386/machdep.c
+++ b/sys/pc98/i386/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.21 1996/12/17 13:26:17 kato Exp $
+ *	$Id: machdep.c,v 1.22 1996/12/18 20:50:44 kato Exp $
  */
 
 #include "npx.h"
@@ -572,7 +572,7 @@ sigreturn(p, uap, retval)
 	fp = (struct sigframe *)
 	     ((caddr_t)scp - offsetof(struct sigframe, sf_sc));
 
-	if (useracc((caddr_t)fp, sizeof (*fp), 0) == 0)
+	if (useracc((caddr_t)fp, sizeof (*fp), B_WRITE) == 0)
 		return(EINVAL);
 
 	/*
@@ -624,7 +624,7 @@ sigreturn(p, uap, retval)
 	regs[tSS] = scp->sc_ss;
 	regs[tISP] = scp->sc_isp;
 
-	if (useracc((caddr_t)scp, sizeof (*scp), 0) == 0)
+	if (useracc((caddr_t)scp, sizeof (*scp), B_WRITE) == 0)
 		return(EINVAL);
 
 	if (scp->sc_onstack & 01)
diff --git a/sys/pc98/pc98/machdep.c b/sys/pc98/pc98/machdep.c
index f49cfac4e93e..970b01679857 100644
--- a/sys/pc98/pc98/machdep.c
+++ b/sys/pc98/pc98/machdep.c
@@ -35,7 +35,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
- *	$Id: machdep.c,v 1.21 1996/12/17 13:26:17 kato Exp $
+ *	$Id: machdep.c,v 1.22 1996/12/18 20:50:44 kato Exp $
  */
 
 #include "npx.h"
@@ -572,7 +572,7 @@ sigreturn(p, uap, retval)
 	fp = (struct sigframe *)
 	     ((caddr_t)scp - offsetof(struct sigframe, sf_sc));
 
-	if (useracc((caddr_t)fp, sizeof (*fp), 0) == 0)
+	if (useracc((caddr_t)fp, sizeof (*fp), B_WRITE) == 0)
 		return(EINVAL);
 
 	/*
@@ -624,7 +624,7 @@ sigreturn(p, uap, retval)
 	regs[tSS] = scp->sc_ss;
 	regs[tISP] = scp->sc_isp;
 
-	if (useracc((caddr_t)scp, sizeof (*scp), 0) == 0)
+	if (useracc((caddr_t)scp, sizeof (*scp), B_WRITE) == 0)
 		return(EINVAL);
 
 	if (scp->sc_onstack & 01)