diff --git a/sys/conf/options.pc98 b/sys/conf/options.pc98
index 9906c9b413eb..79eb917aa4ec 100644
--- a/sys/conf/options.pc98
+++ b/sys/conf/options.pc98
@@ -194,5 +194,4 @@ FPU_ERROR_BROKEN	opt_npx.h
 PC98			opt_global.h
 EPSON_BOUNCEDMA		opt_pc98.h
 EPSON_MEMWIN		opt_pc98.h
-COMPAT_ATDISK		opt_pc98.h
 LINE30			opt_syscons.h
diff --git a/sys/pc98/conf/GENERIC b/sys/pc98/conf/GENERIC
index 66e768143252..991733b6f7bd 100644
--- a/sys/pc98/conf/GENERIC
+++ b/sys/pc98/conf/GENERIC
@@ -57,10 +57,6 @@ options         SYSVSEM			#SYSV-style semaphores
 
 options 	COM_MULTIPORT
 
-#
-#	IBM-PC HDD support
-#options 	COMPAT_ATDISK
-
 # To make an SMP kernel, the next two are needed
 #options 	SMP			# Symmetric MultiProcessor Kernel
 #options 	APIC_IO			# Symmetric (APIC) I/O
diff --git a/sys/pc98/conf/GENERIC98 b/sys/pc98/conf/GENERIC98
index 66e768143252..991733b6f7bd 100644
--- a/sys/pc98/conf/GENERIC98
+++ b/sys/pc98/conf/GENERIC98
@@ -57,10 +57,6 @@ options         SYSVSEM			#SYSV-style semaphores
 
 options 	COM_MULTIPORT
 
-#
-#	IBM-PC HDD support
-#options 	COMPAT_ATDISK
-
 # To make an SMP kernel, the next two are needed
 #options 	SMP			# Symmetric MultiProcessor Kernel
 #options 	APIC_IO			# Symmetric (APIC) I/O
diff --git a/sys/pc98/conf/options.pc98 b/sys/pc98/conf/options.pc98
index 9906c9b413eb..79eb917aa4ec 100644
--- a/sys/pc98/conf/options.pc98
+++ b/sys/pc98/conf/options.pc98
@@ -194,5 +194,4 @@ FPU_ERROR_BROKEN	opt_npx.h
 PC98			opt_global.h
 EPSON_BOUNCEDMA		opt_pc98.h
 EPSON_MEMWIN		opt_pc98.h
-COMPAT_ATDISK		opt_pc98.h
 LINE30			opt_syscons.h
diff --git a/sys/pc98/pc98/diskslice_machdep.c b/sys/pc98/pc98/diskslice_machdep.c
index 95d71396ca08..6c0b2f23b562 100644
--- a/sys/pc98/pc98/diskslice_machdep.c
+++ b/sys/pc98/pc98/diskslice_machdep.c
@@ -42,7 +42,7 @@
  * PC9801 port by KATO Takenor <kato@eclogite.eps.nagoya-u.ac.jp>
  */
 
-#include "opt_pc98.h"
+#include "compat_atdisk.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -81,8 +81,8 @@ static void extended __P((char *dname, dev_t dev, struct disklabel *lp,
 
 #ifdef PC98
 #define DPBLKNO(cyl,hd,sect) ((cyl)*(lp->d_secpercyl))
-#ifdef COMPAT_ATDISK
-int     atcompat_dsinit __P((char *dname, dev_t dev,
+#if	NCOMPAT_ATDISK > 0
+int     atcompat_dsinit __P((dev_t dev,
 		 struct disklabel *lp, struct diskslices **sspp));
 #endif
 #endif
@@ -312,7 +312,7 @@ dsinit(dev, lp, sspp)
 		ssp->dss_nslices = BASE_SLICE + 1;
 		goto done;
 	}
-#ifdef COMPAT_ATDISK
+#if NCOMPAT_ATDISK > 0
 	/* 
 	 * Check magic number of 'extended format' for PC-9801.
 	 * If no magic, it may be formatted on IBM-PC.
@@ -324,7 +324,7 @@ dsinit(dev, lp, sspp)
 		/* IBM-PC HDD */
 		bp->b_flags = B_INVAL | B_AGE;
 		brelse(bp);
-		return atcompat_dsinit(devtoname(bp->b_dev), dev, lp, sspp);
+		return atcompat_dsinit(dev, lp, sspp);
 	}
 #endif
 	dp0 = (struct dos_partition *)(cp + 512);