diff --git a/sys/boot/pc98/libpc98/biosdisk.c b/sys/boot/pc98/libpc98/biosdisk.c
index d55722d6883..3ec6c57112d 100644
--- a/sys/boot/pc98/libpc98/biosdisk.c
+++ b/sys/boot/pc98/libpc98/biosdisk.c
@@ -118,9 +118,9 @@ static void	bd_printbsdslice(struct open_disk *od, daddr_t offset,
 
 static int	bd_init(void);
 static int	bd_strategy(void *devdata, int flag, daddr_t dblk,
-		    size_t size, char *buf, size_t *rsize);
+		    size_t offset, size_t size, char *buf, size_t *rsize);
 static int	bd_realstrategy(void *devdata, int flag, daddr_t dblk,
-		    size_t size, char *buf, size_t *rsize);
+		    size_t offset, size_t size, char *buf, size_t *rsize);
 static int	bd_open(struct open_file *f, ...);
 static int	bd_close(struct open_file *f);
 static void	bd_print(int verbose);