diff --git a/sys/dev/ata/ata-disk.c b/sys/dev/ata/ata-disk.c
index df753c534a4e..0cd0a0f95c7e 100644
--- a/sys/dev/ata/ata-disk.c
+++ b/sys/dev/ata/ata-disk.c
@@ -126,6 +126,10 @@ ad_attach(device_t dev)
     adp->disk->d_name = "ad";
     adp->disk->d_drv1 = dev;
     adp->disk->d_maxsize = ch->dma.max_iosize ? ch->dma.max_iosize : DFLTPHYS;
+    if (atadev->param.support.command2 & ATA_SUPPORT_ADDRESS48)
+	adp->disk->d_maxsize = min(adp->disk->d_maxsize, 65536 * DEV_BSIZE);
+    else					/* 28bit ATA command limit */
+	adp->disk->d_maxsize = min(adp->disk->d_maxsize, 256 * DEV_BSIZE);
     adp->disk->d_sectorsize = DEV_BSIZE;
     adp->disk->d_mediasize = DEV_BSIZE * (off_t)adp->total_secs;
     adp->disk->d_fwsectors = adp->sectors;