diff --git a/flash.h b/flash.h
index 55e218c..850bf33 100644
--- a/flash.h
+++ b/flash.h
@@ -101,6 +101,7 @@
 #define WINBOND_ID		0xDA	/* Winbond */
 #define W_29C011		0xC1
 #define W_29C020C		0x45
+#define W_29C040P		0x46
 #define W_39V040FA		0x34
 #define W_39V040A		0x3D
 #define W_39V040B		0x54