diff --git a/internal/ttlcache/piece.go b/internal/ttlcache/piece.go
index c1f8782..4c0da96 100644
--- a/internal/ttlcache/piece.go
+++ b/internal/ttlcache/piece.go
@@ -31,7 +31,7 @@ func (this *Piece) IncreaseInt64(key uint64, delta int64, expiredAt int64) (resu
 	this.locker.Lock()
 	item, ok := this.m[key]
 	if ok {
-		result := types.Int64(item.Value) + delta
+		result = types.Int64(item.Value) + delta
 		item.Value = result
 		item.expiredAt = expiredAt
 	} else {