diff --git a/ESP32-IDF_ESPNOW-Transmitter/main/espnow_transmitter.c b/ESP32-IDF_ESPNOW-Transmitter/main/espnow_transmitter.c
index 907a9c139..41261255b 100644
--- a/ESP32-IDF_ESPNOW-Transmitter/main/espnow_transmitter.c
+++ b/ESP32-IDF_ESPNOW-Transmitter/main/espnow_transmitter.c
@@ -27,6 +27,7 @@
 #include "esp_netif.h"
 #include "esp_wifi.h"
 #include "esp_log.h"
+#include "esp_err.h"
 #include "esp_mac.h"
 #include "esp_now.h"
 #include "esp_crc.h"