diff --git a/include/coreinit/baseheap.h b/include/coreinit/baseheap.h
index 3c62b2a..fd83ee8 100644
--- a/include/coreinit/baseheap.h
+++ b/include/coreinit/baseheap.h
@@ -11,15 +11,14 @@
 extern "C" {
 #endif
 
-typedef uint32_t MEMBaseHeapType;
 typedef void *MEMHeapHandle;
 
-enum MEMBaseHeapType
+typedef enum MEMBaseHeapType
 {
    MEM_BASE_HEAP_MEM1   = 0,
    MEM_BASE_HEAP_MEM2   = 1,
    MEM_BASE_HEAP_FG     = 8,
-};
+} MEMBaseHeapType;
 
 MEMBaseHeapType
 MEMGetArena(MEMHeapHandle handle);
diff --git a/include/coreinit/event.h b/include/coreinit/event.h
index 9600195..0395271 100644
--- a/include/coreinit/event.h
+++ b/include/coreinit/event.h
@@ -18,16 +18,15 @@ extern "C" {
 #endif
 
 typedef struct OSEvent OSEvent;
-typedef uint32_t OSEventMode;
 
-enum OSEventMode
+typedef enum OSEventMode
 {
    //! A manual event will only reset when OSResetEvent is called.
    OS_EVENT_MODE_MANUAL    = 0,
 
    //! An auto event will reset everytime a thread is woken.
    OS_EVENT_MODE_AUTO      = 1,
-};
+} OSEventMode;
 
 #define OS_EVENT_TAG 0x65566E54u
 
diff --git a/include/coreinit/exception.h b/include/coreinit/exception.h
index e000bce..d0ec70a 100644
--- a/include/coreinit/exception.h
+++ b/include/coreinit/exception.h
@@ -14,7 +14,7 @@ extern "C" {
 typedef uint32_t OSExceptionType;
 typedef BOOL (*OSExceptionCallbackFn)(OSContext *context);
 
-enum OSExceptionType
+typedef enum OSExceptionType
 {
    OS_EXCEPTION_TYPE_SYSTEM_RESET         = 0,
    OS_EXCEPTION_TYPE_MACHINE_CHECK        = 1,
@@ -31,7 +31,7 @@ enum OSExceptionType
    OS_EXCEPTION_TYPE_BREAKPOINT           = 12,
    OS_EXCEPTION_TYPE_SYSTEM_INTERRUPT     = 13,
    OS_EXCEPTION_TYPE_ICI                  = 14,
-};
+} OSExceptionType;
 
 OSExceptionCallbackFn
 OSSetExceptionCallback(OSExceptionType exceptionType,
diff --git a/include/coreinit/expandedheap.h b/include/coreinit/expandedheap.h
index 0c3b8d6..b6293eb 100644
--- a/include/coreinit/expandedheap.h
+++ b/include/coreinit/expandedheap.h
@@ -11,27 +11,24 @@
 extern "C" {
 #endif
 
-typedef struct MEMExpandedHeap MEMExpandedHeap;
-
-typedef uint32_t MEMExpHeapMode;
-typedef uint32_t MEMExpHeapDirection;
+typedef struct MEMExpandedHeap MEMExpandedHeap;;
 
 struct MEMExpandedHeap
 {
 };
 UNKNOWN_SIZE(MEMExpandedHeap);
 
-enum MEMExpHeapMode
+typedef enum MEMExpHeapMode
 {
    MEM_EXP_HEAP_MODE_FIRST_FREE     = 0,
    MEM_EXP_HEAP_MODE_NEAREST_SIZE   = 1,
-};
+} MEMExpHeapMode;
 
-enum MEMExpHeapDirection
+typedef enum MEMExpHeapDirection
 {
    MEM_EXP_HEAP_DIR_FROM_TOP        = 0,
    MEM_EXP_HEAP_DIR_FROM_BOTTOM     = 1,
-};
+} MEMExpHeapDirection;
 
 MEMExpandedHeap *
 MEMCreateExpHeap(MEMExpandedHeap *heap, uint32_t size);
diff --git a/include/coreinit/frameheap.h b/include/coreinit/frameheap.h
index eeaaa64..6e8ce04 100644
--- a/include/coreinit/frameheap.h
+++ b/include/coreinit/frameheap.h
@@ -11,13 +11,11 @@
 extern "C" {
 #endif
 
-typedef uint32_t MEMFrameHeapFreeMode;
-
-enum MEMFrameHeapFreeMode
+typedef enum MEMFrameHeapFreeMode
 {
    MEM_FRAME_HEAP_FREE_FROM_BOTTOM  = 1 << 0,
    MEM_FRAME_HEAP_FREE_FROM_TOP     = 1 << 1,
-};
+} MEMFrameHeapFreeMode;
 
 MEMFrameHeap *
 MEMCreateFrmHeap(MEMFrameHeap *heap,
diff --git a/include/coreinit/messagequeue.h b/include/coreinit/messagequeue.h
index 713e4e1..c81fe4f 100644
--- a/include/coreinit/messagequeue.h
+++ b/include/coreinit/messagequeue.h
@@ -11,13 +11,11 @@
 extern "C" {
 #endif
 
-typedef uint32_t OSMessageFlags;
-
-enum OSMessageFlags
+typedef enum OSMessageFlags
 {
    OS_MESSAGE_QUEUE_BLOCKING        = 1 << 0,
    OS_MESSAGE_QUEUE_HIGH_PRIORITY   = 1 << 1,
-};
+} OSMessageFlags;
 
 struct OSMessage
 {
diff --git a/include/coreinit/taskqueue.h b/include/coreinit/taskqueue.h
index 2bef9d5..4a15b23 100644
--- a/include/coreinit/taskqueue.h
+++ b/include/coreinit/taskqueue.h
@@ -17,17 +17,15 @@ typedef struct MPTaskInfo MPTaskInfo;
 typedef struct MPTaskQueue MPTaskQueue;
 typedef struct MPTaskQueueInfo MPTaskQueueInfo;
 
-typedef uint32_t MPTaskState;
-
 typedef uint32_t (*MPTaskFunc)(uint32_t, uint32_t);
 
-enum MPTaskState
+typedef enum MPTaskState
 {
   MP_TASK_STATE_INITIALISED = 1 << 0,
   MP_TASK_STATE_READY       = 1 << 1,
   MP_TASK_STATE_RUNNING     = 1 << 2,
   MP_TASK_STATE_FINISHED    = 1 << 3,
-};
+} MPTaskState;
 
 struct MPTaskInfo
 {
diff --git a/include/coreinit/thread.h b/include/coreinit/thread.h
index 492e9be..7e6779b 100644
--- a/include/coreinit/thread.h
+++ b/include/coreinit/thread.h
@@ -34,15 +34,20 @@ typedef struct OSMutex OSMutex;
 typedef struct OSMutexQueue OSMutexQueue;
 typedef struct OSThread OSThread;
 
+//! A value from enum OS_THREAD_STATE.
 typedef uint8_t OSThreadState;
+
+//! A value from enum OS_THREAD_REQUEST.
 typedef uint32_t OSThreadRequest;
+
+//! A bitfield of enum OS_THREAD_ATTRIB.
 typedef uint8_t OSThreadAttributes;
 
 typedef int (*OSThreadEntryPointFn)(int argc, const char **argv);
 typedef void (*OSThreadCleanupCallbackFn)(OSThread *thread, void *stack);
 typedef void (*OSThreadDeallocatorFn)(OSThread *thread, void *stack);
 
-enum OSThreadState
+enum OS_THREAD_STATE
 {
    OS_THREAD_STATE_NONE             = 0,
 
@@ -59,14 +64,14 @@ enum OSThreadState
    OS_THREAD_STATE_MORIBUND         = 1 << 3,
 };
 
-enum OSThreadRequest
+enum OS_THREAD_REQUEST
 {
    OS_THREAD_REQUEST_NONE           = 0,
    OS_THREAD_REQUEST_SUSPEND        = 1,
    OS_THREAD_REQUEST_CANCEL         = 2,
 };
 
-enum OSThreadAttributes
+enum OS_THREAD_ATTRIB
 {
    //! Allow the thread to run on CPU0.
    OS_THREAD_ATTRIB_AFFINITY_CPU0   = 1 << 0,
@@ -167,13 +172,21 @@ CHECK_OFFSET(OSFastMutexQueue, 0x04, tail);
 CHECK_SIZE(OSFastMutexQueue, 0x08);
 
 #define OS_THREAD_TAG 0x74487244u
-
+#pragma pack(push, 1)
 struct OSThread
 {
    OSContext context;
+
+   //! Should always be set to the value OS_THREAD_TAG.
    uint32_t tag;
+
+   //! Bitfield of OS_THREAD_STATE
    OSThreadState state;
+
+   //! Bitfield of OS_THREAD_ATTRIB
    OSThreadAttributes attr;
+
+   //! Unique thread ID
    uint16_t id;
 
    //! Suspend count (increased by OSSuspendThread).
@@ -252,8 +265,10 @@ struct OSThread
 
    //! Queue of threads waiting for a thread to be suspended.
    OSThreadQueue suspendQueue;
+
    UNKNOWN(0x69c - 0x5f4);
 };
+#pragma pack(pop)
 CHECK_OFFSET(OSThread, 0x320, tag);
 CHECK_OFFSET(OSThread, 0x324, state);
 CHECK_OFFSET(OSThread, 0x325, attr);
diff --git a/include/gx2/state.h b/include/gx2/state.h
index 0f6d4b2..8aefb99 100644
--- a/include/gx2/state.h
+++ b/include/gx2/state.h
@@ -11,16 +11,14 @@
 extern "C" {
 #endif
 
-typedef uint32_t GX2InitAttributes;
-
-enum GX2InitAttributes
+typedef enum GX2InitAttributes
 {
 	GX2_INIT_END = 0,
 	GX2_INIT_CMD_BUF_BASE = 1,
 	GX2_INIT_CMD_BUF_POOL_SIZE = 2,
 	GX2_INIT_ARGC = 7,
 	GX2_INIT_ARGV = 8,
-};
+} GX2InitAttributes;
 
 void
 GX2Init(uint32_t *attributes);