diff --git a/src/platform/acpi.cpp b/src/platform/acpi.cpp
index d2ccf6a..36589aa 100644
--- a/src/platform/acpi.cpp
+++ b/src/platform/acpi.cpp
@@ -10,6 +10,60 @@
 Mutex ACPI::controllerMutex;
 volatile ACPI* ACPI::controller = nullptr;
 
+enum LAPIC_VALUES {
+  LAPIC_DISABLE = 0x10000,
+  LAPIC_SW_ENABLE = 0x100,
+  LAPIC_CPUFOCUS = 0x200,
+  LAPIC_NMI = (4 << 8),
+  TMR_PERIODIC = 0x20000,
+  TMR_BASEDIV = (1 << 20),
+};
+
+enum IOAPIC_FIELDS {
+  IOAPIC_REGSEL = 0x0, IOAPIC_REGWIN = 0x10,
+};
+
+enum IOAPIC_REGS {
+  IOAPIC_ID = 0x0, IOAPIC_VER = 0x1, IOAPIC_REDTBL = 0x10,
+};
+
+struct ACPI::Header {
+  uint32_t signature;
+  uint32_t length;
+  uint8_t revision;
+  uint8_t checksum;
+  uint8_t oem[6];
+  uint8_t oemTableId[8];
+  uint32_t oemRevision;
+  uint32_t creatorId;
+  uint32_t creatorRevision;
+};
+struct ACPI::Madt : Header {
+  uint32_t localApicAddr;
+  uint32_t flags;
+};
+struct ACPI::ApicHeader {
+  uint8_t type;
+  uint8_t length;
+};
+struct ACPI::ApicLocalApic : ApicHeader {
+  uint8_t acpiProcessorId;
+  uint8_t apicId;
+  uint32_t flags;
+};
+struct ACPI::ApicIoApic : ApicHeader {
+  uint8_t ioApicId;
+  uint8_t reserved;
+  uint32_t ioApicAddress;
+  uint32_t globalSystemInterruptBase;
+};
+struct ACPI::ApicInterruptOverride : ApicHeader {
+  uint8_t bus;
+  uint8_t source;
+  uint32_t interrupt;
+  uint16_t flags;
+};
+
 ACPI* ACPI::getController() {
   if (controller) return const_cast<ACPI*>(controller);
   Mutex::CriticalLock lock(controllerMutex);
@@ -132,7 +186,7 @@ void ACPI::ParseApic(const Madt *madt) {
   Pagetable::map(localApicAddr);
 
   const uint8_t *p = reinterpret_cast<const uint8_t*>(madt + 1);
-  const uint8_t *end = p + (madt->header.length - sizeof(Madt));
+  const uint8_t *end = p + (madt->Header::length - sizeof(Madt));
 
   while (p < end) {
     const ApicHeader *header = reinterpret_cast<const ApicHeader*>(p);
@@ -141,15 +195,14 @@ void ACPI::ParseApic(const Madt *madt) {
     uint16_t type = header->type;
     uint16_t length = header->length;
     if (type == 0) {
-      const ApicLocalApic *s = reinterpret_cast<const ApicLocalApic*>(p);
+      const ApicLocalApic *s = reinterpret_cast<const ApicLocalApic*>(header);
       acpiCpuIds[acpiCpuCount++] = s->apicId;
     } else if (type == 1) {
-      const ApicIoApic *s = reinterpret_cast<const ApicIoApic*>(p);
+      const ApicIoApic *s = reinterpret_cast<const ApicIoApic*>(header);
       ioApicAddr = reinterpret_cast<char*>(uintptr_t(s->ioApicAddress));
       Pagetable::map(ioApicAddr);
     } else if (type == 2) {
-      const ApicInterruptOverride *s =
-          reinterpret_cast<const ApicInterruptOverride*>(p);
+      const ApicInterruptOverride *s = reinterpret_cast<const ApicInterruptOverride*>(header);
       (void)s;
       // TODO: handle interrupt overrides
     }
diff --git a/src/platform/include/acpi.hpp b/src/platform/include/acpi.hpp
index 5185ee2..159af28 100644
--- a/src/platform/include/acpi.hpp
+++ b/src/platform/include/acpi.hpp
@@ -27,66 +27,6 @@ class ACPI {
     LAPIC_TMRDIV = 0x3E0,
     LAPIC_LAST = 0x38F,
   };
-
- private:
-  enum LAPIC_VALUES {
-    LAPIC_DISABLE = 0x10000,
-    LAPIC_SW_ENABLE = 0x100,
-    LAPIC_CPUFOCUS = 0x200,
-    LAPIC_NMI = (4 << 8),
-    TMR_PERIODIC = 0x20000,
-    TMR_BASEDIV = (1 << 20),
-  };
-
-  enum IOAPIC_FIELDS {
-    IOAPIC_REGSEL = 0x0, IOAPIC_REGWIN = 0x10,
-  };
-
-  enum IOAPIC_REGS {
-    IOAPIC_ID = 0x0, IOAPIC_VER = 0x1, IOAPIC_REDTBL = 0x10,
-  };
-
-  struct Header {
-    uint32_t signature;
-    uint32_t length;
-    uint8_t revision;
-    uint8_t checksum;
-    uint8_t oem[6];
-    uint8_t oemTableId[8];
-    uint32_t oemRevision;
-    uint32_t creatorId;
-    uint32_t creatorRevision;
-  };
-  struct Madt {
-    Header header;
-    uint32_t localApicAddr;
-    uint32_t flags;
-  };
-  struct ApicHeader {
-    uint8_t type;
-    uint8_t length;
-  };
-  struct ApicLocalApic {
-    ApicHeader header;
-    uint8_t acpiProcessorId;
-    uint8_t apicId;
-    uint32_t flags;
-  };
-  struct ApicIoApic {
-    ApicHeader header;
-    uint8_t ioApicId;
-    uint8_t reserved;
-    uint32_t ioApicAddress;
-    uint32_t globalSystemInterruptBase;
-  };
-  struct ApicInterruptOverride {
-    ApicHeader header;
-    uint8_t bus;
-    uint8_t source;
-    uint32_t interrupt;
-    uint16_t flags;
-  };
-
   union IOApicRedir {
     struct {
       uint8_t vector :8;
@@ -104,6 +44,13 @@ class ACPI {
   };
 
  private:
+  struct Header;
+  struct Madt;
+  struct ApicHeader;
+  struct ApicLocalApic;
+  struct ApicIoApic;
+  struct ApicInterruptOverride;
+
   static Mutex controllerMutex;
   static volatile ACPI *controller;