diff --git a/sys/stand/efiboot/efiblock.c b/sys/stand/efiboot/efiblock.c
index 465511a5834b..5417b4e6a4cb 100644
--- a/sys/stand/efiboot/efiblock.c
+++ b/sys/stand/efiboot/efiblock.c
@@ -419,7 +419,7 @@ efi_block_find_partitions_gpt(struct efi_block_dev *bdev)
 	void *buf;
 	UINTN sz;
 
-	status = efi_block_read(bdev, GPT_HDR_BLKNO * DEV_BSIZE, &hdr,
+	status = efi_block_read(bdev, GPT_HDR_BLKNO * bdev->bio->Media->BlockSize, &hdr,
 	    sizeof(hdr));
 	if (EFI_ERROR(status)) {
 		return EIO;
@@ -436,7 +436,7 @@ efi_block_find_partitions_gpt(struct efi_block_dev *bdev)
 		return ENOMEM;
 
 	status = efi_block_read(bdev,
-	    le64toh(hdr.hdr_lba_table) * DEV_BSIZE, buf, sz);
+	    le64toh(hdr.hdr_lba_table) * bdev->bio->Media->BlockSize, buf, sz);
 	if (EFI_ERROR(status)) {
 		FreePool(buf);
 		return EIO;