diff --git a/src/mainboard/apple/macbook21/mainboard.c b/src/mainboard/apple/macbook21/mainboard.c
index 509784f337..447837ba54 100644
--- a/src/mainboard/apple/macbook21/mainboard.c
+++ b/src/mainboard/apple/macbook21/mainboard.c
@@ -17,7 +17,7 @@ static acpi_cstate_t cst_entries[] = {
 			.space_id = ACPI_ADDRESS_SPACE_FIXED,
 			.bit_width = ACPI_FFIXEDHW_VENDOR_INTEL,
 			.bit_offset = ACPI_FFIXEDHW_CLASS_MWAIT,
-			.access_size = 0,
+			.access_size = ACPI_ACCESS_SIZE_UNDEFINED,
 			.addrl = 0,
 			.addrh = 0,
 		}
@@ -30,7 +30,7 @@ static acpi_cstate_t cst_entries[] = {
 			.space_id = ACPI_ADDRESS_SPACE_FIXED,
 			.bit_width = ACPI_FFIXEDHW_VENDOR_INTEL,
 			.bit_offset = ACPI_FFIXEDHW_CLASS_MWAIT,
-			.access_size = 0,
+			.access_size = ACPI_ACCESS_SIZE_UNDEFINED,
 			.addrl = 0x10,
 			.addrh = 0,
 		}
diff --git a/src/mainboard/lenovo/x60/mainboard.c b/src/mainboard/lenovo/x60/mainboard.c
index 5210040384..f6930bb93f 100644
--- a/src/mainboard/lenovo/x60/mainboard.c
+++ b/src/mainboard/lenovo/x60/mainboard.c
@@ -20,7 +20,7 @@
 		.space_id = ACPI_ADDRESS_SPACE_FIXED,		\
 		.bit_width = ACPI_FFIXEDHW_VENDOR_INTEL,	\
 		.bit_offset = ACPI_FFIXEDHW_CLASS_MWAIT,	\
-		.access_size = 0,				\
+		.access_size = ACPI_ACCESS_SIZE_UNDEFINED,	\
 		.addrl = (((state) << 4) | (sub_state)),	\
 		.addrh = 0,					\
 	}