diff --git a/src/mqtt_client_wrapper.cpp b/src/mqtt_client_wrapper.cpp
index 319490d..b868120 100644
--- a/src/mqtt_client_wrapper.cpp
+++ b/src/mqtt_client_wrapper.cpp
@@ -214,8 +214,6 @@ void mqtt_client_thread_func()
 
         while (!mqtt_restart_required && g_running)
         {
-            auto now = std::chrono::steady_clock::now();
-
             try
             {
                 send_heartbeat();
@@ -224,7 +222,6 @@ void mqtt_client_thread_func()
             {
                 LOG_ERROR(std::string("[MQTT] Heartbeat error: ") + e.what());
             }
-            last_heartbeat = now;
 
             std::this_thread::sleep_for(heartbeat_interval); // 固定周期
         }