diff --git a/mboxd_msg.h b/mboxd_msg.h
index 44a2f91..7d81d7a 100644
--- a/mboxd_msg.h
+++ b/mboxd_msg.h
@@ -18,8 +18,13 @@
 #ifndef MBOXD_MSG_H
 #define MBOXD_MSG_H
 
-#define NO_BMC_EVENT	false
-#define SET_BMC_EVENT	true
+#include "common.h"
+
+/* Estimate as to how long (milliseconds) it takes to access a MB from flash */
+#define FLASH_ACCESS_MS_PER_MB		8000
+
+#define NO_BMC_EVENT			false
+#define SET_BMC_EVENT			true
 
 struct mbox_msg {
 	uint8_t command;