diff --git a/controllers/constant/constant.go b/controllers/constant/constant.go
index 1448d792..dba9d48b 100644
--- a/controllers/constant/constant.go
+++ b/controllers/constant/constant.go
@@ -27,4 +27,5 @@ const (
 	ConfigVolumeName         = "config"
 	InitConfigVolumeName     = "init-config"
 	TLSVolumeName            = "tls"
+	DefaultTLSMode           = "prefer"
 )
diff --git a/controllers/greptimedbcluster/deployers/frontend.go b/controllers/greptimedbcluster/deployers/frontend.go
index ca039a6b..d88366e1 100644
--- a/controllers/greptimedbcluster/deployers/frontend.go
+++ b/controllers/greptimedbcluster/deployers/frontend.go
@@ -253,7 +253,7 @@ func (b *frontendBuilder) generateMainContainerArgs() []string {
 
 	if b.Cluster.Spec.Frontend != nil && b.Cluster.Spec.Frontend.TLS != nil {
 		args = append(args, []string{
-			"--tls-mode", "require",
+			"--tls-mode", constant.DefaultTLSMode,
 			"--tls-cert-path", path.Join(constant.GreptimeDBTLSDir, TLSCrtSecretKey),
 			"--tls-key-path", path.Join(constant.GreptimeDBTLSDir, TLSKeySecretKey),
 		}...)