diff --git a/simulator.h b/simulator.h
index 1e2ed2c..85fc8fc 100644
--- a/simulator.h
+++ b/simulator.h
@@ -100,6 +100,7 @@ typedef enum {
 
   RX_ENABLE_PIN,
   TX_ENABLE_PIN,
+  DEBUG_LED_PIN,
 
   PIN_NB  /* End of PINS marker; Put all new pins before this one */
 } pin_t;