diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 6d707545f775..9ee11b41ba5d 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -966,8 +966,8 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_root *root,
 	void *p;
 
 	rbio = kzalloc(sizeof(*rbio) + num_pages * sizeof(struct page *) * 2 +
-		       DIV_ROUND_UP(stripe_npages, BITS_PER_LONG / 8),
-			GFP_NOFS);
+		       DIV_ROUND_UP(stripe_npages, BITS_PER_LONG) *
+		       sizeof(long), GFP_NOFS);
 	if (!rbio)
 		return ERR_PTR(-ENOMEM);
 
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 681db07f25ea..b1a68530e911 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2813,7 +2813,7 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity)
 
 static inline int scrub_calc_parity_bitmap_len(int nsectors)
 {
-	return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * (BITS_PER_LONG / 8);
+	return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * sizeof(long);
 }
 
 static void scrub_parity_get(struct scrub_parity *sparity)