diff --git a/watch-faces/complication/simon_face.c b/watch-faces/complication/simon_face.c
index ef8b0095..642b32a2 100644
--- a/watch-faces/complication/simon_face.c
+++ b/watch-faces/complication/simon_face.c
@@ -23,6 +23,7 @@
  */
 
 #include "simon_face.h"
+#include "delay.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>