diff --git a/flash.h b/flash.h
index 8a6f766..c487701 100644
--- a/flash.h
+++ b/flash.h
@@ -58,6 +58,7 @@
 #define W_49F002U         0x0B	/* Winbond w29c020c device code */
 
 #define ST_ID       	  0x20
+#define ST_M29F040B       0xE2
 #define ST_M29F400BT      0xD5
 
 #define MSYSTEMS_ID       0x156f