diff --git a/sys/fs/msdosfs/bpb.h b/sys/fs/msdosfs/bpb.h
index c9bf27cdc693..addacd22fa15 100644
--- a/sys/fs/msdosfs/bpb.h
+++ b/sys/fs/msdosfs/bpb.h
@@ -167,6 +167,4 @@ struct fsinfo {
 	u_int8_t fsinxtfree[4];
 	u_int8_t fsifill2[12];
 	u_int8_t fsisig3[4];
-	u_int8_t fsifill3[508];
-	u_int8_t fsisig4[4];
 };
diff --git a/sys/fs/msdosfs/msdosfs_fat.c b/sys/fs/msdosfs/msdosfs_fat.c
index c0b53a4e367b..b77f2d61fe58 100644
--- a/sys/fs/msdosfs/msdosfs_fat.c
+++ b/sys/fs/msdosfs/msdosfs_fat.c
@@ -376,7 +376,7 @@ updatefats(pmp, bp, fatbn)
 				+ ffs(pmp->pm_inusemap[cn / N_INUSEBITS]
 				      ^ (u_int)-1) - 1;
 		}
-		if (bread(pmp->pm_devvp, pmp->pm_fsinfo, fsi_size(pmp), 
+		if (bread(pmp->pm_devvp, pmp->pm_fsinfo, pmp->pm_bpcluster,
 		    NOCRED, &bpn) != 0) {
 			/*
 			 * Ignore the error, but turn off FSInfo update for the future.
diff --git a/sys/fs/msdosfs/msdosfs_vfsops.c b/sys/fs/msdosfs/msdosfs_vfsops.c
index 3b53b0af8135..8c30fde389f5 100644
--- a/sys/fs/msdosfs/msdosfs_vfsops.c
+++ b/sys/fs/msdosfs/msdosfs_vfsops.c
@@ -644,14 +644,13 @@ mountmsdosfs(struct vnode *devvp, struct mount *mp, struct thread *td)
 	if (pmp->pm_fsinfo) {
 		struct fsinfo *fp;
 
-		if ((error = bread(devvp, pmp->pm_fsinfo, fsi_size(pmp),
+		if ((error = bread(devvp, pmp->pm_fsinfo, pmp->pm_bpcluster,
 		    NOCRED, &bp)) != 0)
 			goto error_exit;
 		fp = (struct fsinfo *)bp->b_data;
 		if (!bcmp(fp->fsisig1, "RRaA", 4)
 		    && !bcmp(fp->fsisig2, "rrAa", 4)
-		    && !bcmp(fp->fsisig3, "\0\0\125\252", 4)
-		    && !bcmp(fp->fsisig4, "\0\0\125\252", 4)) {
+		    && !bcmp(fp->fsisig3, "\0\0\125\252", 4)) {
 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
 			if (pmp->pm_nxtfree == 0xffffffff)
 				pmp->pm_nxtfree = CLUST_FIRST;
diff --git a/sys/fs/msdosfs/msdosfsmount.h b/sys/fs/msdosfs/msdosfsmount.h
index f3c08d647206..088467951f12 100644
--- a/sys/fs/msdosfs/msdosfsmount.h
+++ b/sys/fs/msdosfs/msdosfsmount.h
@@ -210,12 +210,6 @@ struct msdosfs_fileno {
 	 ? roottobn((pmp), (dirofs)) \
 	 : cntobn((pmp), (dirclu)))
 
-/*
- * Calculate fsinfo block size
- */
-#define	fsi_size(pmp) \
-	(1024 << ((pmp)->pm_BlkPerSec >> 2))
-
 void msdosfs_fileno_init(struct mount *);
 void msdosfs_fileno_free(struct mount *);
 uint32_t msdosfs_fileno_map(struct mount *, uint64_t);