diff --git a/sdk/xtdk/hltypes.h b/sdk/xtdk/hltypes.h
index 27e823d..a6a489f 100644
--- a/sdk/xtdk/hltypes.h
+++ b/sdk/xtdk/hltypes.h
@@ -319,6 +319,17 @@ typedef struct _ACPI_FADT
     GENERIC_ADDRESS SleepStatusReg;
 } PACKED ACPI_FADT, *PACPI_FADT;
 
+/* ACPI High Precision Event Timer (HPET) table structure */
+typedef struct _ACPI_HPET
+{
+    ACPI_DESCRIPTION_HEADER Header;
+    ULONG EventTimerBlockId;
+    GENERIC_ADDRESS BaseAddress;
+    UCHAR HpetNumber;
+    USHORT MinimumTick;
+    UCHAR PageProtectionAndOem;
+} PACKED ACPI_HPET, *PACPI_HPET;
+
 /* ACPI Multiple APIC Description Table (MADT) structure */
 typedef struct _ACPI_MADT
 {
@@ -328,6 +339,26 @@ typedef struct _ACPI_MADT
     ULONG ApicTables[];
 } PACKED ACPI_MADT, *PACPI_MADT;
 
+/* ACPI Interrupt Override MADT subtable structure */
+typedef struct _ACPI_MADT_INTERRUPT_OVERRIDE
+{
+    ACPI_SUBTABLE_HEADER Header;
+    UCHAR Bus;
+    UCHAR SourceIrq;
+    ULONG GlobalSystemInterrupt;
+    USHORT Flags;
+} PACKED ACPI_MADT_INTERRUPT_OVERRIDE, *PACPI_MADT_INTERRUPT_OVERRIDE;
+
+/* ACPI IO APIC MADT subtable structure */
+typedef struct _ACPI_MADT_IOAPIC
+{
+    ACPI_SUBTABLE_HEADER Header;
+    UCHAR IoApicId;
+    UCHAR Reserved;
+    ULONG IoApicAddress;
+    ULONG GlobalIrqBase;
+} PACKED ACPI_MADT_IOAPIC, *PACPI_MADT_IOAPIC;
+
 /* ACPI Local APIC MADT subtable structure */
 typedef struct _ACPI_MADT_LOCAL_APIC
 {
diff --git a/sdk/xtdk/xtstruct.h b/sdk/xtdk/xtstruct.h
index a407660..cdd4455 100644
--- a/sdk/xtdk/xtstruct.h
+++ b/sdk/xtdk/xtstruct.h
@@ -66,8 +66,12 @@ typedef enum _WAIT_TYPE WAIT_TYPE, *PWAIT_TYPE;
 typedef struct _ACPI_CACHE_LIST ACPI_CACHE_LIST, *PACPI_CACHE_LIST;
 typedef struct _ACPI_DESCRIPTION_HEADER ACPI_DESCRIPTION_HEADER, *PACPI_DESCRIPTION_HEADER;
 typedef struct _ACPI_FADT ACPI_FADT, *PACPI_FADT;
+typedef struct _ACPI_HPET ACPI_HPET, *PACPI_HPET;
 typedef struct _ACPI_MADT ACPI_MADT, *PACPI_MADT;
-typedef struct _ACPI_MADT_TABLE_LOCAL_APIC ACPI_MADT_TABLE_LOCAL_APIC, *PACPI_MADT_TABLE_LOCAL_APIC;
+typedef struct _ACPI_MADT_INTERRUPT_OVERRIDE ACPI_MADT_INTERRUPT_OVERRIDE, *PACPI_MADT_INTERRUPT_OVERRIDE;
+typedef struct _ACPI_MADT_IOAPIC ACPI_MADT_IOAPIC, *PACPI_MADT_IOAPIC;
+typedef struct _ACPI_MADT_LOCAL_APIC ACPI_MADT_LOCAL_APIC, *PACPI_MADT_LOCAL_APIC;
+typedef struct _ACPI_MADT_LOCAL_X2APIC ACPI_MADT_LOCAL_X2APIC, *PACPI_MADT_LOCAL_X2APIC;
 typedef struct _ACPI_RSDP ACPI_RSDP, *PACPI_RSDP;
 typedef struct _ACPI_RSDT ACPI_RSDT, *PACPI_RSDT;
 typedef struct _ACPI_SUBTABLE_HEADER ACPI_SUBTABLE_HEADER, *PACPI_SUBTABLE_HEADER;