diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 53575a45f7d1..673e32be88fa 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1299,7 +1299,9 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check)
 static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio, u64 *raid_map)
 {
 	if (raid_map) {
-		if (raid_map[bbio->num_stripes - 1] == RAID6_Q_STRIPE)
+		int real_stripes = bbio->num_stripes - bbio->num_tgtdevs;
+
+		if (raid_map[real_stripes - 1] == RAID6_Q_STRIPE)
 			return 3;
 		else
 			return 2;
@@ -1420,7 +1422,8 @@ static int scrub_setup_recheck_block(struct scrub_ctx *sctx,
 
 			scrub_stripe_index_and_offset(logical, raid_map,
 						      mapped_length,
-						      bbio->num_stripes,
+						      bbio->num_stripes -
+						      bbio->num_tgtdevs,
 						      mirror_index,
 						      &stripe_index,
 						      &stripe_offset);