diff --git a/src/southbridge/amd/agesa/hudson/fadt.c b/src/southbridge/amd/agesa/hudson/fadt.c
index 220b327de0..ef11c861dd 100644
--- a/src/southbridge/amd/agesa/hudson/fadt.c
+++ b/src/southbridge/amd/agesa/hudson/fadt.c
@@ -77,7 +77,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->x_pm1a_cnt_blk.space_id = ACPI_ADDRESS_SPACE_IO;
 	fadt->x_pm1a_cnt_blk.bit_width = 16;
 	fadt->x_pm1a_cnt_blk.bit_offset = 0;
-	fadt->x_pm1a_cnt_blk.access_size = 0;
+	fadt->x_pm1a_cnt_blk.access_size = ACPI_ACCESS_SIZE_UNDEFINED;
 	fadt->x_pm1a_cnt_blk.addrl = ACPI_PM1_CNT_BLK;
 	fadt->x_pm1a_cnt_blk.addrh = 0x0;
 
diff --git a/src/southbridge/amd/cimx/sb800/fadt.c b/src/southbridge/amd/cimx/sb800/fadt.c
index 3868d2461c..a5c27d6525 100644
--- a/src/southbridge/amd/cimx/sb800/fadt.c
+++ b/src/southbridge/amd/cimx/sb800/fadt.c
@@ -101,7 +101,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->x_pm1a_cnt_blk.space_id = ACPI_ADDRESS_SPACE_IO;
 	fadt->x_pm1a_cnt_blk.bit_width = 16;
 	fadt->x_pm1a_cnt_blk.bit_offset = 0;
-	fadt->x_pm1a_cnt_blk.access_size = 0;
+	fadt->x_pm1a_cnt_blk.access_size = ACPI_ACCESS_SIZE_UNDEFINED;
 	fadt->x_pm1a_cnt_blk.addrl = PM1_CNT_BLK_ADDRESS;
 	fadt->x_pm1a_cnt_blk.addrh = 0x0;
 
diff --git a/src/southbridge/amd/pi/hudson/fadt.c b/src/southbridge/amd/pi/hudson/fadt.c
index 0b73921e7b..319bdf380f 100644
--- a/src/southbridge/amd/pi/hudson/fadt.c
+++ b/src/southbridge/amd/pi/hudson/fadt.c
@@ -79,7 +79,7 @@ void acpi_fill_fadt(acpi_fadt_t *fadt)
 	fadt->x_pm1a_cnt_blk.space_id = ACPI_ADDRESS_SPACE_IO;
 	fadt->x_pm1a_cnt_blk.bit_width = 16;
 	fadt->x_pm1a_cnt_blk.bit_offset = 0;
-	fadt->x_pm1a_cnt_blk.access_size = 0;
+	fadt->x_pm1a_cnt_blk.access_size = ACPI_ACCESS_SIZE_UNDEFINED;
 	fadt->x_pm1a_cnt_blk.addrl = ACPI_PM1_CNT_BLK;
 	fadt->x_pm1a_cnt_blk.addrh = 0x0;