diff --git a/ESP32-IDF_ESPNOW-Receiver/main/receiver.h b/ESP32-IDF_ESPNOW-Receiver/main/receiver.h
index 8dc24bf77..a82ff5159 100644
--- a/ESP32-IDF_ESPNOW-Receiver/main/receiver.h
+++ b/ESP32-IDF_ESPNOW-Receiver/main/receiver.h
@@ -7,5 +7,6 @@
 
 void wifi_init(void);
 void transmission_init(void);
+void onDataReceived (const uint8_t *mac_addr, const uint8_t *data, uint8_t data_len);
 
 #endif
\ No newline at end of file