diff --git a/block.go b/block.go
index 19425ba4c4..e3760df76a 100644
--- a/block.go
+++ b/block.go
@@ -474,9 +474,7 @@ func (pb *Block) CleanTombstones(dest string, c Compactor) (bool, error) {
 	numStones := 0
 
 	pb.tombstones.Iter(func(id uint64, ivs Intervals) error {
-		for range ivs {
-			numStones++
-		}
+		numStones += len(ivs)
 
 		return nil
 	})