diff --git a/flash.h b/flash.h
index b86ec7d..f646908 100644
--- a/flash.h
+++ b/flash.h
@@ -7,6 +7,9 @@
 #define FLASH_DIRTY	0x00
 #define FLASH_ERASED	0x01
 
+/* Estimate as to how long (milliseconds) it takes to access a MB from flash */
+#define FLASH_ACCESS_MS_PER_MB		8000
+
 #include "mbox.h"
 
 int flash_dev_init(struct mbox_context *context);