diff --git a/sdk/xtdk/ketypes.h b/sdk/xtdk/ketypes.h
index f34a097..b3c4799 100644
--- a/sdk/xtdk/ketypes.h
+++ b/sdk/xtdk/ketypes.h
@@ -645,7 +645,7 @@ typedef struct _KTHREAD
     LIST_ENTRY ThreadListEntry;
     UCHAR LargeStack;
     UCHAR PowerState;
-    UCHAR NpxIrql;
+    UCHAR NpxRunLevel;
     UCHAR Spare5;
     BOOLEAN AutoAlignment;
     UCHAR Iopl;
diff --git a/xtoskrnl/ke/i686/kthread.cc b/xtoskrnl/ke/i686/kthread.cc
index b4a924c..6a619a6 100644
--- a/xtoskrnl/ke/i686/kthread.cc
+++ b/xtoskrnl/ke/i686/kthread.cc
@@ -66,7 +66,7 @@ KE::KThread::InitializeThreadContext(IN PKTHREAD Thread,
 
         /* Disable coprocessor floating point state */
         Thread->NpxState = NPX_STATE_UNLOADED;
-        Thread->Header.NpxIrql = PASSIVE_LEVEL;
+        Thread->NpxRunLevel = PASSIVE_LEVEL;
 
         /* Set initial floating point state */
         FxSaveFormat = (PFX_SAVE_FORMAT)ContextRecord->ExtendedRegisters;
diff --git a/xtoskrnl/ke/kthread.cc b/xtoskrnl/ke/kthread.cc
index 5892b7d..51955ee 100644
--- a/xtoskrnl/ke/kthread.cc
+++ b/xtoskrnl/ke/kthread.cc
@@ -144,8 +144,9 @@ KE::KThread::InitializeThread(IN PKPROCESS Process,
     Allocation = FALSE;
 
     /* Initialize thread dispatcher header */
-    Thread->Header.Type = ThreadObject;
     Thread->Header.SignalState = 0;
+    Thread->Header.Size = sizeof(KTHREAD) / sizeof(LONG);
+    Thread->Header.Type = ThreadObject;
 
     /* Initialize thread wait list */
     RTL::LinkedList::InitializeListHead(&Thread->Header.WaitListHead);
@@ -269,7 +270,7 @@ KE::KThread::InitializeThread(IN PKPROCESS Process,
  */
 XTAPI
 VOID
-KE::KThread::StartThread(IN PKTHREAD Thread)
+KE::KThread::StartThread(IN OUT PKTHREAD Thread)
 {
     UNIMPLEMENTED;
 }