diff --git a/sbin/newfs_msdos/mkfs_msdos.c b/sbin/newfs_msdos/mkfs_msdos.c
index 065e3c5f4192..423fbbcadcc5 100644
--- a/sbin/newfs_msdos/mkfs_msdos.c
+++ b/sbin/newfs_msdos/mkfs_msdos.c
@@ -249,7 +249,7 @@ mkfs_msdos(const char *fname, const char *dtype, const struct msdos_options *op)
     ssize_t n;
     time_t now;
     u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
-    u_int extra_res, alignment, saved_x, attempts=0;
+    u_int extra_res, alignment, alignto, saved_x, attempts=0;
     bool set_res, set_spf, set_spc;
     int fd, fd1, rv;
     struct msdos_options o = *op;
@@ -412,8 +412,12 @@ mkfs_msdos(const char *fname, const char *dtype, const struct msdos_options *op)
 	}
 	bpb.bpbFATs = o.num_FAT;
     }
-    if (o.directory_entries)
-	bpb.bpbRootDirEnts = o.directory_entries;
+    if (o.directory_entries) {
+	bpb.bpbRootDirEnts = roundup(o.directory_entries,
+	    bpb.bpbBytesPerSec / sizeof(struct de));
+	if (bpb.bpbBytesPerSec == 0 || o.directory_entries >= MAXU16)
+	    bpb.bpbRootDirEnts = MAXU16;
+    }
     if (o.media_descriptor_set) {
 	if (o.media_descriptor < 0xf0) {
 	    warnx("illegal media descriptor (%#x)", o.media_descriptor);
@@ -564,14 +568,20 @@ mkfs_msdos(const char *fname, const char *dtype, const struct msdos_options *op)
 	    x1 += (bpb.bpbBigFATsecs - 1) * bpb.bpbFATs;
 	}
 	if (set_res) {
-	    /* attempt to align root directory */
-	    alignment = (bpb.bpbResSectors + bpb.bpbBigFATsecs * bpb.bpbFATs) %
-		bpb.bpbSecPerClust;
 	    if (o.align)
-		extra_res += bpb.bpbSecPerClust - alignment;
+		alignto = bpb.bpbSecPerClust;
+	    else
+		alignto = PAGE_SIZE / bpb.bpbBytesPerSec;
+	    if (alignto > 1) {
+		/* align data clusters */
+		alignment = (bpb.bpbResSectors + bpb.bpbBigFATsecs * bpb.bpbFATs + rds) %
+		    alignto;
+		if (alignment != 0)
+		    extra_res += alignto - alignment;
+	    }
 	}
 	attempts++;
-    } while (o.align && alignment != 0 && attempts < 2);
+    } while (alignment != 0 && attempts < 2);
     if (o.align && alignment != 0)
 	warnx("warning: Alignment failed.");
 
diff --git a/sbin/newfs_msdos/newfs_msdos.8 b/sbin/newfs_msdos/newfs_msdos.8
index efa69c058453..816b5fc867b4 100644
--- a/sbin/newfs_msdos/newfs_msdos.8
+++ b/sbin/newfs_msdos/newfs_msdos.8
@@ -23,7 +23,7 @@
 .\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 .\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd January 12, 2024
+.Dd June 2, 2024
 .Dt NEWFS_MSDOS 8
 .Os
 .Sh NAME
@@ -91,7 +91,13 @@ A suffix s, k, m, g (lower or upper case)
 appended to the offset specifies that the
 number is in sectors, kilobytes, megabytes or gigabytes, respectively.
 .It Fl A
-Attempt to cluster align root directory, useful for SD card.
+Attempt to cluster align the data area, useful for SD card.
+If neither the
+.Fl A
+nor
+.Fl r
+option is used, the number of reserved sectors is set to a value that aligns
+the start of the data area to a multiple of the page size of the host.
 .It Fl B Ar boot
 Get bootstrap from file.
 .It Fl C Ar create-size
@@ -167,6 +173,12 @@ is 2.
 Number of hidden sectors.
 .It Fl r Ar reserved
 Number of reserved sectors.
+If neither the
+.Fl A
+nor
+.Fl r
+option is used, the number of reserved sectors is set to a value that aligns
+the start of the data area to a multiple of the page size of the host.
 .It Fl s Ar total
 File system size.
 .It Fl u Ar track-size