diff --git a/lib/blob/blobstore.c b/lib/blob/blobstore.c
index 991f032ee..5a025a115 100644
--- a/lib/blob/blobstore.c
+++ b/lib/blob/blobstore.c
@@ -665,7 +665,7 @@ _spdk_blob_serialize_extent(const struct spdk_blob *blob,
 	struct spdk_blob_md_descriptor_extent *desc;
 	size_t cur_sz;
 	uint64_t i, extent_idx;
-	uint32_t lba, lba_per_cluster, lba_count;
+	uint64_t lba, lba_per_cluster, lba_count;
 
 	/* The buffer must have room for at least one extent */
 	cur_sz = sizeof(struct spdk_blob_md_descriptor) + sizeof(desc->extents[0]);
diff --git a/lib/blob/blobstore.h b/lib/blob/blobstore.h
index 2084e5cfe..56a7a5d42 100644
--- a/lib/blob/blobstore.h
+++ b/lib/blob/blobstore.h
@@ -432,7 +432,7 @@ _spdk_bs_dev_lba_to_page(struct spdk_bs_dev *bs_dev, uint64_t lba)
 static inline uint64_t
 _spdk_bs_cluster_to_page(struct spdk_blob_store *bs, uint32_t cluster)
 {
-	return cluster * bs->pages_per_cluster;
+	return (uint64_t)cluster * bs->pages_per_cluster;
 }
 
 static inline uint32_t
@@ -446,7 +446,7 @@ _spdk_bs_page_to_cluster(struct spdk_blob_store *bs, uint64_t page)
 static inline uint64_t
 _spdk_bs_cluster_to_lba(struct spdk_blob_store *bs, uint32_t cluster)
 {
-	return cluster * (bs->cluster_sz / bs->dev->blocklen);
+	return (uint64_t)cluster * (bs->cluster_sz / bs->dev->blocklen);
 }
 
 static inline uint32_t