diff --git a/fs/bcachefs/buckets.h b/fs/bcachefs/buckets.h
index f192809f50cf..0eff05c79c65 100644
--- a/fs/bcachefs/buckets.h
+++ b/fs/bcachefs/buckets.h
@@ -180,7 +180,7 @@ static inline u64 bch2_dev_buckets_reserved(struct bch_dev *ca, enum bch_waterma
 
 	switch (watermark) {
 	case BCH_WATERMARK_NR:
-		unreachable();
+		BUG();
 	case BCH_WATERMARK_stripe:
 		reserved += ca->mi.nbuckets >> 6;
 		fallthrough;