diff --git a/kernel/model/box.go b/kernel/model/box.go
index ffcf8bdcb..7765e0bf6 100644
--- a/kernel/model/box.go
+++ b/kernel/model/box.go
@@ -708,6 +708,9 @@ func VacuumDataIndex() {
 		humanize.BytesCustomCeil(uint64(oldAssetContentDbSize), 2), humanize.BytesCustomCeil(uint64(newAssetContentDbSize), 2))
 
 	releaseSize := (oldsyDbSize - newSyDbSize) + (oldHistoryDbSize - newHistoryDbSize) + (oldAssetContentDbSize - newAssetContentDbSize)
+	if releaseSize < 0 {
+		releaseSize = 0
+	}
 	msg := fmt.Sprintf(Conf.language(271), humanize.BytesCustomCeil(uint64(releaseSize), 2))
 	util.PushMsg(msg, 7000)
 }