diff --git a/src/include/acpi/acpi.h b/src/include/acpi/acpi.h
index 7b0f339..a9ec077 100644
--- a/src/include/acpi/acpi.h
+++ b/src/include/acpi/acpi.h
@@ -41,6 +41,7 @@
 
 #define ACPI_TABLE_CREATOR	"COREBOOT"  /* Must be exactly 8 bytes long! */
 #define OEM_ID			"COREv4"    /* Must be exactly 6 bytes long! */
+#define ACPI_DSDT_REV_1		0x01        /* DSDT revision: ACPI v1 */
 #define ACPI_DSDT_REV_2		0x02        /* DSDT revision: ACPI v2.0 and greater */
 
 #if !defined(__ASSEMBLER__) && !defined(__ACPI__)