diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 630bce68bf38..b61db9db3ca5 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -54,7 +54,7 @@
 #define SMBSLVDAT	(0xC + piix4_smba)
 
 /* count for request_region */
-#define SMBIOSIZE	8
+#define SMBIOSIZE	9
 
 /* PCI Address Constants */
 #define SMBBA		0x090