diff --git a/sw/airborne/boards/tiny_2.1.h b/sw/airborne/boards/tiny_2.1.h
index daa57d607f..572f2b6cf0 100644
--- a/sw/airborne/boards/tiny_2.1.h
+++ b/sw/airborne/boards/tiny_2.1.h
@@ -37,18 +37,21 @@
 /* Peripheral bus clock freq. */
 #define PCLK (CCLK / PBSD_VAL)
 
+/* green */
 #ifndef USE_LED_1
 #define USE_LED_1 1
 #endif
 #define LED_1_BANK 1
 #define LED_1_PIN 17
 
+/* red */
 #ifndef USE_LED_2
 #define USE_LED_2 1
 #endif
 #define LED_2_BANK 1
 #define LED_2_PIN 16
 
+/* yellow */
 #ifndef USE_LED_3
 #define USE_LED_3 1
 #endif