diff --git a/boards/nrf52840dk/include/arduino_iomap.h b/boards/nrf52840dk/include/arduino_iomap.h
index 2a0fd0a5ac..2bcda63454 100644
--- a/boards/nrf52840dk/include/arduino_iomap.h
+++ b/boards/nrf52840dk/include/arduino_iomap.h
@@ -60,6 +60,13 @@ extern "C" {
 #define ARDUINO_I2C_UNO         I2C_DEV(0)
 /** @} */
 
+/**
+ * @name    on-board LED (LED1/D25)
+ * @{
+ */
+#define ARDUINO_LED     (24)
+/** @} */
+
 /**
  * @name   Mapping of MCU pins to Arduino pins
  * @{