diff --git a/thermo_sensor_v2.ino b/thermo_sensor_v2.ino
index 809a46b..70879eb 100644
--- a/thermo_sensor_v2.ino
+++ b/thermo_sensor_v2.ino
@@ -21,6 +21,7 @@ IPAddress subnet(MY_NET);
 ModbusIP mb;
 DHT dht(DHTPIN, DHTTYPE);
 char id[64];
+bool dht_read_error = false;
 
 #define REGISTER_CURRENT_TEMP 0
 #define REGISTER_CURRENT_HUM 1
@@ -35,6 +36,7 @@ unsigned long current = 0;
 Modbus::ResultCode OnModbusRequest(Modbus::FunctionCode fc, const Modbus::RequestData data) 
 {
   last_poll = current;
+  if (dht_read_error) return Modbus::EX_ILLEGAL_VALUE;
   return Modbus::EX_SUCCESS;
 }
 
@@ -81,6 +83,8 @@ void UpdateDHTData()
 	float t = dht.readTemperature();
 	cur_hum = (int)(h * 100);
 	cur_t = (int)(t * 100);
+  if (cur_t == 2147483647 && cur_hum == 2147483647) dht_read_error = true;
+  else dht_read_error = false;
 }
 
 unsigned long last_read = 0;