diff --git a/block/blk-merge.c b/block/blk-merge.c
index c874931bae6b..86c4c1ef8742 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -154,7 +154,7 @@ static inline unsigned get_max_io_size(struct request_queue *q,
 	if (max_sectors > start_offset)
 		return max_sectors - start_offset;
 
-	return sectors & (lbs - 1);
+	return sectors & ~(lbs - 1);
 }
 
 static inline unsigned get_max_segment_size(const struct request_queue *q,