diff --git a/src/serial_AT.cpp b/src/serial_AT.cpp
index ced5653..13e68e4 100644
--- a/src/serial_AT.cpp
+++ b/src/serial_AT.cpp
@@ -72,7 +72,7 @@ void start_http_server(int port)
                           j["ok"] = true;
                           j["server"] = {{"device_type", "tbox"}, {"imei", imei}, {"fw", "b-v2.1.0"}};
 
-                          res.set_content(j.dump(2), "application/json");
+                          res.set_content(j.dump(-1), "application/json");
                       });
 
     http_thread = std::thread(