diff --git a/board/sandbox/sandbox.c b/board/sandbox/sandbox.c
index 9ca1eca..438f9a4 100644
--- a/board/sandbox/sandbox.c
+++ b/board/sandbox/sandbox.c
@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <cpu_func.h>
 #include <cros_ec.h>
 #include <dm.h>
 #include <led.h>