diff --git a/service/alerting/elasticsearch/engine.go b/service/alerting/elasticsearch/engine.go
index 9ed4bc40..a50c53e9 100644
--- a/service/alerting/elasticsearch/engine.go
+++ b/service/alerting/elasticsearch/engine.go
@@ -288,7 +288,7 @@ func (engine *Engine) generateTimeFilter(rule *alerting.Rule, filterParam *alert
 		)
 		intervalDuration, err := time.ParseDuration(rule.Metrics.BucketSize)
 		if err != nil {
-			return nil, fmt.Errorf("parse bucket size of rule %s error: %v", rule.Name, err)
+			return nil, fmt.Errorf("parse bucket size [%s] of rule [%s] error: %v", rule.Metrics.BucketSize, rule.Name, err)
 		}
 		if intervalDuration / time.Hour >= 1 {
 			units = "h"