diff --git a/reactos/lib/ntdll/csr/lpc.c b/reactos/lib/ntdll/csr/lpc.c
index 0625d48b6ed..5f49355d314 100644
--- a/reactos/lib/ntdll/csr/lpc.c
+++ b/reactos/lib/ntdll/csr/lpc.c
@@ -104,7 +104,7 @@ CsrClientCallServer(PCSRSS_API_REQUEST Request,
       return (STATUS_UNSUCCESSFUL);
     }
 
-   Request->Header.DataSize = Length - sizeof(LPC_MESSAGE);
+   Request->Header.DataSize = Length - LPC_MESSAGE_BASE_SIZE;
    Request->Header.MessageSize = Length;
 
    Status = NtRequestWaitReplyPort(WindowsApiPort,
diff --git a/reactos/lib/ntdll/dbg/debug.c b/reactos/lib/ntdll/dbg/debug.c
index 4d4b0b93813..c10351aa10e 100644
--- a/reactos/lib/ntdll/dbg/debug.c
+++ b/reactos/lib/ntdll/dbg/debug.c
@@ -12,6 +12,7 @@
 /* INCLUDES *****************************************************************/
 
 #include <ddk/ntddk.h>
+#include <ntos.h>
 #include <ntdll/rtl.h>
 #include <rosrtl/string.h>
 #include <rosrtl/thread.h>
diff --git a/reactos/lib/ntdll/ldr/res.c b/reactos/lib/ntdll/ldr/res.c
index 546ee4da19e..49054223a5e 100644
--- a/reactos/lib/ntdll/ldr/res.c
+++ b/reactos/lib/ntdll/ldr/res.c
@@ -25,11 +25,12 @@
 
 #include <reactos/config.h>
 #include <ddk/ntddk.h>
+#include <ntos.h>
+#include <ntos/ldrtypes.h>
 #include <windows.h>
 #include <string.h>
 #include <wchar.h>
 #include <ntdll/ldr.h>
-#include <ntos/minmax.h>
 
 #define NDEBUG
 #include <ntdll/ntdll.h>
diff --git a/reactos/lib/ntdll/ldr/startup.c b/reactos/lib/ntdll/ldr/startup.c
index f76e6c2c7d9..91293c4823d 100644
--- a/reactos/lib/ntdll/ldr/startup.c
+++ b/reactos/lib/ntdll/ldr/startup.c
@@ -32,8 +32,8 @@ VOID LdrpInitLoader(VOID);
 
 extern unsigned int _image_base__;
 
-static CRITICAL_SECTION PebLock;
-static CRITICAL_SECTION LoaderLock;
+static RTL_CRITICAL_SECTION PebLock;
+static RTL_CRITICAL_SECTION LoaderLock;
 static RTL_BITMAP TlsBitMap;
 PLDR_MODULE ExeModule;
 
diff --git a/reactos/lib/ntdll/ldr/utils.c b/reactos/lib/ntdll/ldr/utils.c
index 093b75bce0b..9ceef9d716e 100644
--- a/reactos/lib/ntdll/ldr/utils.c
+++ b/reactos/lib/ntdll/ldr/utils.c
@@ -21,11 +21,12 @@
 
 #include <reactos/config.h>
 #include <ddk/ntddk.h>
+#include <ntos.h>
 #include <windows.h>
 #include <string.h>
 #include <wchar.h>
 #include <ntdll/ldr.h>
-#include <ntos/minmax.h>
+#include <ntdll/rtl.h>
 
 #define LDRP_PROCESS_CREATION_TIME 0x8000000
 
@@ -264,7 +265,7 @@ LdrpInitializeTlsForProccess(VOID)
                                                               TRUE,
                                                               IMAGE_DIRECTORY_ENTRY_TLS,
                                                               NULL);
-               assert(Module->TlsIndex < LdrpTlsCount);
+               ASSERT(Module->TlsIndex < LdrpTlsCount);
                TlsData = &LdrpTlsArray[Module->TlsIndex];
                TlsData->StartAddressOfRawData = (PVOID)TlsDirectory->StartAddressOfRawData;
                TlsData->TlsDataSize = TlsDirectory->EndAddressOfRawData - TlsDirectory->StartAddressOfRawData;
@@ -466,7 +467,7 @@ LdrAddModuleEntry(PVOID ImageBase,
   PLDR_MODULE Module;
 
   Module = RtlAllocateHeap(RtlGetProcessHeap(), 0, sizeof (LDR_MODULE));
-  assert(Module);
+  ASSERT(Module);
   memset(Module, 0, sizeof(LDR_MODULE));
   Module->BaseAddress = (PVOID)ImageBase;
   Module->EntryPoint = NTHeaders->OptionalHeader.AddressOfEntryPoint;
@@ -2076,7 +2077,7 @@ LdrpLoadModule(IN PWSTR SearchPath OPTIONAL,
         DPRINT("Mapped %wZ at %x\n", &FullDosName, ImageBase);
         if (MappedAsDataFile)
           {
-            assert(NULL != BaseAddress);
+            ASSERT(NULL != BaseAddress);
             if (NULL != BaseAddress)
               {
                 *BaseAddress = (PVOID) ((char *) *BaseAddress + 1);
diff --git a/reactos/lib/ntdll/ntdll.xml b/reactos/lib/ntdll/ntdll.xml
index d4fde463359..c9c07692ce5 100644
--- a/reactos/lib/ntdll/ntdll.xml
+++ b/reactos/lib/ntdll/ntdll.xml
@@ -3,6 +3,9 @@
 	<importlibrary definition="def/ntdll.def" />
 	<define name="__NTDLL__" />
 	<define name="_DISABLE_TIDENTS" />
+	<define name="__USE_W32API" />
+	<define name="_WIN32_WINNT">0x0502</define>
+	<define name="_NTOSKRNL_" />
 	<library>rtl</library>
 	<library>rosrtl</library>
 	<library>string</library>
diff --git a/reactos/lib/ntdll/rtl/apc.c b/reactos/lib/ntdll/rtl/apc.c
index 09184c904cb..313073d0d52 100644
--- a/reactos/lib/ntdll/rtl/apc.c
+++ b/reactos/lib/ntdll/rtl/apc.c
@@ -26,7 +26,7 @@
 
 /* INCLUDES *****************************************************************/
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <string.h>
 #include <debug.h>
 
diff --git a/reactos/lib/ntdll/rtl/atom.c b/reactos/lib/ntdll/rtl/atom.c
index e61ce506cdb..7a2952022d1 100644
--- a/reactos/lib/ntdll/rtl/atom.c
+++ b/reactos/lib/ntdll/rtl/atom.c
@@ -11,7 +11,7 @@
 
 /* INCLUDES *****************************************************************/
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <ntdll/rtl.h>
 #include <ntos/heap.h>
 
@@ -653,11 +653,11 @@ RtlpInitAtomTableLock(PRTL_ATOM_TABLE AtomTable)
 {
    AtomTable->Lock = RtlAllocateHeap(RtlGetProcessHeap(),
 				     HEAP_ZERO_MEMORY,
-				     sizeof(CRITICAL_SECTION));
+				     sizeof(RTL_CRITICAL_SECTION));
    if (AtomTable->Lock == NULL)
      return STATUS_NO_MEMORY;
 
-   RtlInitializeCriticalSection((PCRITICAL_SECTION)AtomTable->Lock);
+   RtlInitializeCriticalSection((PRTL_CRITICAL_SECTION)AtomTable->Lock);
 
    return STATUS_SUCCESS;
 }
@@ -668,7 +668,7 @@ RtlpDestroyAtomTableLock(PRTL_ATOM_TABLE AtomTable)
 {
    if (AtomTable->Lock)
      {
-	RtlDeleteCriticalSection((PCRITICAL_SECTION)AtomTable->Lock);
+	RtlDeleteCriticalSection((PRTL_CRITICAL_SECTION)AtomTable->Lock);
 	RtlFreeHeap(RtlGetProcessHeap(),
 		    0,
 		    AtomTable->Lock);
@@ -680,7 +680,7 @@ RtlpDestroyAtomTableLock(PRTL_ATOM_TABLE AtomTable)
 static BOOLEAN
 RtlpLockAtomTable(PRTL_ATOM_TABLE AtomTable)
 {
-   RtlEnterCriticalSection((PCRITICAL_SECTION)AtomTable->Lock);
+   RtlEnterCriticalSection((PRTL_CRITICAL_SECTION)AtomTable->Lock);
    return TRUE;
 }
 
@@ -688,7 +688,7 @@ RtlpLockAtomTable(PRTL_ATOM_TABLE AtomTable)
 static VOID
 RtlpUnlockAtomTable(PRTL_ATOM_TABLE AtomTable)
 {
-   RtlLeaveCriticalSection((PCRITICAL_SECTION)AtomTable->Lock);
+   RtlLeaveCriticalSection((PRTL_CRITICAL_SECTION)AtomTable->Lock);
 }
 
 
diff --git a/reactos/lib/ntdll/rtl/callback.c b/reactos/lib/ntdll/rtl/callback.c
index a9c8436b9f2..f2e6ccfebeb 100644
--- a/reactos/lib/ntdll/rtl/callback.c
+++ b/reactos/lib/ntdll/rtl/callback.c
@@ -9,15 +9,15 @@
 
 /* INCLUDES *****************************************************************/
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <string.h>
 #include <napi/teb.h>
 
 
 /* TYPES *********************************************************************/
 
-typedef NTSTATUS STDCALL_FUNC (*CALLBACK_FUNCTION)(PVOID Argument,
-					      ULONG ArgumentLength);
+typedef NTSTATUS (STDCALL *KERNEL_CALLBACK_FUNCTION)(PVOID Argument,
+                                                    ULONG ArgumentLength);
 
 /* FUNCTIONS *****************************************************************/
 
@@ -28,10 +28,10 @@ KiUserCallbackDispatcher(ULONG RoutineIndex,
 {
    PPEB Peb;
    NTSTATUS Status;
-   CALLBACK_FUNCTION Callback;
+   KERNEL_CALLBACK_FUNCTION Callback;
 
    Peb = NtCurrentPeb();
-   Callback = (CALLBACK_FUNCTION)Peb->KernelCallbackTable[RoutineIndex];
+   Callback = (KERNEL_CALLBACK_FUNCTION)Peb->KernelCallbackTable[RoutineIndex];
    Status = Callback(Argument, ArgumentLength);
    ZwCallbackReturn(NULL, 0, Status);
 }
diff --git a/reactos/lib/ntdll/rtl/critical.c b/reactos/lib/ntdll/rtl/critical.c
index da3de89097e..895b38639e8 100644
--- a/reactos/lib/ntdll/rtl/critical.c
+++ b/reactos/lib/ntdll/rtl/critical.c
@@ -12,9 +12,9 @@
 
 /* INCLUDES ******************************************************************/
 
-#include <ddk/ntddk.h>
+#include <windows.h>
+#include <ntos.h>
 #include <ntdll/rtl.h>
-#include <ntos/synch.h>
 
 #define NDEBUG
 #include <ntdll/ntdll.h>
diff --git a/reactos/lib/ntdll/rtl/dbgbuffer.c b/reactos/lib/ntdll/rtl/dbgbuffer.c
index 443cb3d5953..4c0523698dc 100644
--- a/reactos/lib/ntdll/rtl/dbgbuffer.c
+++ b/reactos/lib/ntdll/rtl/dbgbuffer.c
@@ -36,7 +36,7 @@
 #include <napi/teb.h>
 #include <ntdll/rtl.h>
 #include <ntdll/ldr.h>
-#include <ddk/ntddk.h>
+#include <ntos.h>
 
 #include <rosrtl/thread.h>
 
diff --git a/reactos/lib/ntdll/rtl/exception.c b/reactos/lib/ntdll/rtl/exception.c
index 2e4811e3fed..2cfc4e5725b 100644
--- a/reactos/lib/ntdll/rtl/exception.c
+++ b/reactos/lib/ntdll/rtl/exception.c
@@ -14,15 +14,16 @@
 
 /* INCLUDES *****************************************************************/
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <windows.h>
 #include <string.h>
+#include <ntdll/rtl.h>
 #include <napi/teb.h>
 
 #define NDEBUG
 #include <debug.h>
 
-static CRITICAL_SECTION RtlpVectoredExceptionLock;
+static RTL_CRITICAL_SECTION RtlpVectoredExceptionLock;
 static LIST_ENTRY RtlpVectoredExceptionHead;
 
 typedef struct _RTL_VECTORED_EXCEPTION_HANDLER
diff --git a/reactos/lib/ntdll/rtl/libsupp.c b/reactos/lib/ntdll/rtl/libsupp.c
index bca664e3878..4a50fc11109 100644
--- a/reactos/lib/ntdll/rtl/libsupp.c
+++ b/reactos/lib/ntdll/rtl/libsupp.c
@@ -9,7 +9,7 @@
  *
  */
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <ntdll/rtl.h>
 #include <ctype.h>
 #include <ntos/minmax.h>
diff --git a/reactos/lib/ntdll/rtl/message.c b/reactos/lib/ntdll/rtl/message.c
index 1354055f4c8..9a0891f2260 100644
--- a/reactos/lib/ntdll/rtl/message.c
+++ b/reactos/lib/ntdll/rtl/message.c
@@ -11,7 +11,9 @@
 
 /* INCLUDES *****************************************************************/
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
+#include <ntos/ldrtypes.h>
+#include <ddk/ldrfuncs.h>
 
 #define NDEBUG
 #include <ntdll/ntdll.h>
diff --git a/reactos/lib/ntdll/rtl/misc.c b/reactos/lib/ntdll/rtl/misc.c
index 373bb9835d6..12bbc8a9d4b 100644
--- a/reactos/lib/ntdll/rtl/misc.c
+++ b/reactos/lib/ntdll/rtl/misc.c
@@ -12,7 +12,7 @@
 /* INCLUDES *****************************************************************/
 
 #include <windows.h>
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <ntdll/rtl.h>
 
 #define NDEBUG
diff --git a/reactos/lib/ntdll/rtl/path.c b/reactos/lib/ntdll/rtl/path.c
index dc792698a91..4544798b075 100644
--- a/reactos/lib/ntdll/rtl/path.c
+++ b/reactos/lib/ntdll/rtl/path.c
@@ -10,14 +10,12 @@
 
 /* INCLUDES ******************************************************************/
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <ntdll/rtl.h>
 #include <ntos/minmax.h>
 #include <string.h>
 #include <stdio.h>
 #include <ctype.h>
-#include <base.h>
-#include <ddk/obfuncs.h>
 
 #define NDEBUG
 #include <ntdll/ntdll.h>
diff --git a/reactos/lib/ntdll/rtl/process.c b/reactos/lib/ntdll/rtl/process.c
index 02751cc68eb..f26a42026ba 100644
--- a/reactos/lib/ntdll/rtl/process.c
+++ b/reactos/lib/ntdll/rtl/process.c
@@ -11,7 +11,7 @@
 
 /* INCLUDES ****************************************************************/
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <windows.h>
 #include <napi/i386/segment.h>
 #include <ntdll/ldr.h>
diff --git a/reactos/lib/ntdll/rtl/rangelist.c b/reactos/lib/ntdll/rtl/rangelist.c
index b83e4902c1b..6aba4c84f36 100644
--- a/reactos/lib/ntdll/rtl/rangelist.c
+++ b/reactos/lib/ntdll/rtl/rangelist.c
@@ -26,7 +26,8 @@
 
 /* INCLUDES ****************************************************************/
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
+#include <ntdll/rtl.h>
 
 #define NDEBUG
 #include <ntdll/ntdll.h>
diff --git a/reactos/lib/ntdll/rtl/resource.c b/reactos/lib/ntdll/rtl/resource.c
index 913b7aaf8eb..07933e9f56b 100644
--- a/reactos/lib/ntdll/rtl/resource.c
+++ b/reactos/lib/ntdll/rtl/resource.c
@@ -18,9 +18,8 @@
  * The code is based on information published in WDJ January 1999 issue.
  */
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <ntdll/rtl.h>
-#include <ntos/synch.h>
 
 #define NDEBUG
 #include <ntdll/ntdll.h>
diff --git a/reactos/lib/ntdll/stdio/sscanf.c b/reactos/lib/ntdll/stdio/sscanf.c
index 88b7b2affa5..2dd6af361e4 100644
--- a/reactos/lib/ntdll/stdio/sscanf.c
+++ b/reactos/lib/ntdll/stdio/sscanf.c
@@ -1,8 +1,8 @@
 /**/
 
 #include <stdio.h>
-#include <ddk/ntddk.h>
-#include <ntos/heap.h>
+#include <ntos.h>
+#include <ntdll/rtl.h>
 
 #define NDEBUG
 #include <ntdll/ntdll.h>
diff --git a/reactos/lib/ntdll/stdlib/mbstowcs.c b/reactos/lib/ntdll/stdlib/mbstowcs.c
index 5d2cbb76d8f..17e1d9184f1 100644
--- a/reactos/lib/ntdll/stdlib/mbstowcs.c
+++ b/reactos/lib/ntdll/stdlib/mbstowcs.c
@@ -6,7 +6,7 @@
  * PURPOSE:         converts a multi byte string to a unicode string
  */
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <stdlib.h>
 #include <string.h>
 
diff --git a/reactos/lib/ntdll/stdlib/wcstombs.c b/reactos/lib/ntdll/stdlib/wcstombs.c
index a9690c77ba4..f0b068799d3 100644
--- a/reactos/lib/ntdll/stdlib/wcstombs.c
+++ b/reactos/lib/ntdll/stdlib/wcstombs.c
@@ -6,7 +6,7 @@
  * PURPOSE:         converts a unicode string to a multi byte string
  */
 
-#include <ddk/ntddk.h>
+#include <ntos.h>
 #include <stdlib.h>
 #include <string.h>