diff --git a/kernel/model/history.go b/kernel/model/history.go
index b0ce07e38..e339434af 100644
--- a/kernel/model/history.go
+++ b/kernel/model/history.go
@@ -446,7 +446,7 @@ func buildSearchHistoryQueryFilter(query, op, box, table string, typ int) (stmt
 	}
 
 	ago := time.Now().Add(-24 * time.Hour * time.Duration(Conf.Editor.HistoryRetentionDays))
-	stmt += " AND created > '" + fmt.Sprintf("%d", ago.Unix()) + "'"
+	stmt += " AND CAST(created AS INTEGER) > " + fmt.Sprintf("%d", ago.Unix()) + ""
 	return
 }
 
@@ -619,7 +619,7 @@ func clearOutdatedHistoryDir(historyDir string) {
 	}
 
 	// 清理历史库
-	sql.DeleteOutdatedHistories(fmt.Sprintf("%d", ago))
+	sql.DeleteOutdatedHistories(ago)
 }
 
 var boxLatestHistoryTime = map[string]time.Time{}
diff --git a/kernel/sql/history.go b/kernel/sql/history.go
index a53b48f99..5a1dd2760 100644
--- a/kernel/sql/history.go
+++ b/kernel/sql/history.go
@@ -104,8 +104,8 @@ func queryHistory(query string, args ...interface{}) (*sql.Rows, error) {
 	return historyDB.Query(query, args...)
 }
 
-func deleteOutdatedHistories(tx *sql.Tx, before string, context map[string]interface{}) (err error) {
-	stmt := "DELETE FROM histories_fts_case_insensitive WHERE created < ?"
+func deleteOutdatedHistories(tx *sql.Tx, before int64, context map[string]interface{}) (err error) {
+	stmt := "DELETE FROM histories_fts_case_insensitive WHERE CAST(created AS INTEGER) < ?"
 	if err = execStmtTx(tx, stmt, before); nil != err {
 		return
 	}
diff --git a/kernel/sql/queue_history.go b/kernel/sql/queue_history.go
index 418a82160..b9643210a 100644
--- a/kernel/sql/queue_history.go
+++ b/kernel/sql/queue_history.go
@@ -41,7 +41,7 @@ type historyDBQueueOperation struct {
 	action      string // index/deleteOutdated
 
 	histories []*History // index
-	before    string     // deleteOutdated
+	before    int64      // deleteOutdated
 }
 
 func FlushHistoryTxJob() {
@@ -121,7 +121,7 @@ func execHistoryOp(op *historyDBQueueOperation, tx *sql.Tx, context map[string]i
 	return
 }
 
-func DeleteOutdatedHistories(before string) {
+func DeleteOutdatedHistories(before int64) {
 	historyDBQueueLock.Lock()
 	defer historyDBQueueLock.Unlock()