diff --git a/src/service/alert.go b/src/service/alert.go
index f41cb414558f2c275a538aef7f9d8576cc54c8d1..184fcac16d347a2f760afd7d873dd38d28106c60 100644
--- a/src/service/alert.go
+++ b/src/service/alert.go
@@ -686,7 +686,7 @@ func (a *AlertSvc) GetIndexMaxID(indexName ...string) (maxId int, err error) {
 	aggregations := responseMap["aggregations"].(map[string]interface{})
 	maxIDAgg := aggregations["max_id"].(map[string]interface{})
 	maxIDValue := maxIDAgg["value"]
-	maxId = int(maxIDValue.(float64))
+	maxId = cast.ToInt(maxIDValue)
 
 	return maxId, nil
 }