diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index a680c76..737d388 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -713,6 +713,9 @@
 	if (r)
 		goto bad;
 
+	if (bdev_size > THIN_METADATA_MAX_SECTORS)
+		bdev_size = THIN_METADATA_MAX_SECTORS;
+
 	disk_super = dm_block_data(sblock);
 	disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
 	disk_super->version = cpu_to_le32(THIN_VERSION);