diff --git a/Core/Src/f4_can_app.c b/Core/Src/f4_can_app.c
index fb66300..9f670da 100644
--- a/Core/Src/f4_can_app.c
+++ b/Core/Src/f4_can_app.c
@@ -426,6 +426,7 @@ static void CAN_ProcessControlFrame(const uint8_t *rx_data, uint8_t dlc)
     }
 
     CAN_AtomicIncU32(&s_valid_cmd_total);
+    HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_2);
 }
 
 /* =====================================================================