diff --git a/drivers/w1/w1_family.h b/drivers/w1/w1_family.h
index 3053133..3ca1b92 100644
--- a/drivers/w1/w1_family.h
+++ b/drivers/w1/w1_family.h
@@ -33,6 +33,7 @@
 #define W1_THERM_DS1822  	0x22
 #define W1_EEPROM_DS2433  	0x23
 #define W1_THERM_DS18B20 	0x28
+#define W1_EEPROM_DS2431	0x2D
 #define W1_FAMILY_DS2760	0x30
 
 #define MAXNAMELEN		32