diff --git a/lib/libdisk/change.c b/lib/libdisk/change.c
index ca3df9975533..18b8bc3570b6 100644
--- a/lib/libdisk/change.c
+++ b/lib/libdisk/change.c
@@ -26,7 +26,6 @@ Set_Bios_Geom(struct disk *disk, u_long cyl, u_long hd, u_long sect)
 	disk->bios_sect = sect;
 }
 
-/* XXX - parameters should change to fit for PC-98, but I'm not sure */
 void
 Sanitize_Bios_Geom(struct disk *disk)
 {
@@ -34,11 +33,19 @@ Sanitize_Bios_Geom(struct disk *disk)
 
 	sane = 1;
 
+#ifdef PC98
+	if (disk->bios_cyl >= 65536)
+#else
 	if (disk->bios_cyl > 1024)
+#endif
 		sane = 0;
 	if (disk->bios_hd > 16)
 		sane = 0;
+#ifdef PC98
+	if (disk->bios_sect >= 256)
+#else
 	if (disk->bios_sect > 63)
+#endif
 		sane = 0;
 	if (disk->bios_cyl*disk->bios_hd*disk->bios_sect != disk->chunks->size)
 		sane = 0;
@@ -50,11 +57,21 @@ Sanitize_Bios_Geom(struct disk *disk)
 	disk->bios_hd = 16;
 	disk->bios_cyl = disk->chunks->size / (disk->bios_sect*disk->bios_hd);
 
+#ifdef PC98
+	if (disk->bios_cyl < 65536)
+#else
 	if (disk->bios_cyl < 1024)
+#endif
 		return;
 
 	/* Hmm, try harder... */
+#ifdef PC98
+	/* Assume standard SCSI parameter */
+	disk->bios_sect = 128;
+	disk->bios_hd = 8;
+#else
 	disk->bios_hd = 255;
+#endif
 	disk->bios_cyl = disk->chunks->size / (disk->bios_sect*disk->bios_hd);
 
 	return;
diff --git a/usr.sbin/sade/disks.c b/usr.sbin/sade/disks.c
index 992512b203cb..78e700f64173 100644
--- a/usr.sbin/sade/disks.c
+++ b/usr.sbin/sade/disks.c
@@ -96,8 +96,11 @@ print_chunks(Disk *d, int u)
 
     for (i = Total = 0; chunk_info[i]; i++)
 	Total += chunk_info[i]->size;
-#ifndef PC98
+#ifdef PC98
+    if (d->bios_cyl >= 65536 || d->bios_hd > 16 || d->bios_sect >= 256) {
+#else
     if (d->bios_cyl > 65536 || d->bios_hd > 256 || d->bios_sect >= 64) {
+#endif
 	dialog_clear_norefresh();
 	msgConfirm("WARNING:  A geometry of %lu/%lu/%lu for %s is incorrect.  Using\n"
 		   "a more likely geometry.  If this geometry is incorrect or you\n"
@@ -111,7 +114,6 @@ print_chunks(Disk *d, int u)
 	  d->bios_cyl, d->bios_hd, d->bios_sect, d->name);
 	Sanitize_Bios_Geom(d);
     }
-#endif
     attrset(A_NORMAL);
     mvaddstr(0, 0, "Disk name:\t");
     clrtobot();
diff --git a/usr.sbin/sysinstall/disks.c b/usr.sbin/sysinstall/disks.c
index 992512b203cb..78e700f64173 100644
--- a/usr.sbin/sysinstall/disks.c
+++ b/usr.sbin/sysinstall/disks.c
@@ -96,8 +96,11 @@ print_chunks(Disk *d, int u)
 
     for (i = Total = 0; chunk_info[i]; i++)
 	Total += chunk_info[i]->size;
-#ifndef PC98
+#ifdef PC98
+    if (d->bios_cyl >= 65536 || d->bios_hd > 16 || d->bios_sect >= 256) {
+#else
     if (d->bios_cyl > 65536 || d->bios_hd > 256 || d->bios_sect >= 64) {
+#endif
 	dialog_clear_norefresh();
 	msgConfirm("WARNING:  A geometry of %lu/%lu/%lu for %s is incorrect.  Using\n"
 		   "a more likely geometry.  If this geometry is incorrect or you\n"
@@ -111,7 +114,6 @@ print_chunks(Disk *d, int u)
 	  d->bios_cyl, d->bios_hd, d->bios_sect, d->name);
 	Sanitize_Bios_Geom(d);
     }
-#endif
     attrset(A_NORMAL);
     mvaddstr(0, 0, "Disk name:\t");
     clrtobot();