diff --git a/serial_to_mqtt_bridge/serial_to_mqtt.py b/serial_to_mqtt_bridge/serial_to_mqtt.py
index ddd75a9617cb57c9ba64a415953327345a90d675..4a0825f7b22d23047f637ce07df1f62f954edf5b 100755
--- a/serial_to_mqtt_bridge/serial_to_mqtt.py
+++ b/serial_to_mqtt_bridge/serial_to_mqtt.py
@@ -59,7 +59,7 @@ def main(serial_port=None, baud_rate=115200, file_path="sim_data.txt", mqtt_brok
                 # Get the next line from the file
                 line = next(file_reader)
                 cnt = cnt +1
-                msg=line+str(cnt)
+                msg=mqtt_topic+","+line+str(cnt)
                 client.publish(msg)
                 print(f"Sent to MQTT broker={mqtt_broker} in topic={mqtt_topic} msg={msg}")
                 time.sleep(sim_interval)  # Use interval from YAML config