diff --git a/ESP32-IDF_ESPNOW-Transmitter/main/espnow_transmitter.c b/ESP32-IDF_ESPNOW-Transmitter/main/espnow_transmitter.c
index 87fbbafaa..846a0ea46 100644
--- a/ESP32-IDF_ESPNOW-Transmitter/main/espnow_transmitter.c
+++ b/ESP32-IDF_ESPNOW-Transmitter/main/espnow_transmitter.c
@@ -407,4 +407,5 @@ void app_main(void)
 
     wifi_init();
     esp_now_init();
+    esp_now_register_send_cb(onDataSent);
 }