diff --git a/trpc/admin/prometheus_handler.cc b/trpc/admin/prometheus_handler.cc
index 1e6c4d90..252215fe 100644
--- a/trpc/admin/prometheus_handler.cc
+++ b/trpc/admin/prometheus_handler.cc
@@ -79,6 +79,8 @@ bool PrometheusHandler::CheckBasicAuth(std::string token) {
 
 void PrometheusHandler::CommandHandle(http::HttpRequestPtr req, rapidjson::Value& result,
                                       rapidjson::Document::AllocatorType& alloc) {
+  static std::unique_ptr<::prometheus::Serializer> serializer = std::make_unique<::prometheus::TextSerializer>();
+
   std::string prometheus_str = serializer->Serialize(trpc::prometheus::Collect());
 
   std::string token = req->GetHeader("authorization");