diff --git a/include/basetsd.h b/include/basetsd.h
index 9b71d404534..81ada05ff5b 100644
--- a/include/basetsd.h
+++ b/include/basetsd.h
@@ -44,7 +44,7 @@ extern "C" {
  * simply add to the command line:
  *    -D__int8=char -D__int16=short -D__int32=int "-D__int64=long long"
  */
-#ifndef _MSC_VER
+#if !defined(_MSC_VER) && !defined(__WIDL__)
 #  ifndef __int8
 #    define __int8  char
 #  endif
@@ -59,17 +59,17 @@ extern "C" {
 #  endif
 #endif /* !defined(_MSC_VER) */
 
-typedef signed __int8    INT8, *PINT8;
-typedef signed __int16   INT16, *PINT16;
-typedef signed __int32   INT32, *PINT32;
+typedef signed char      INT8, *PINT8;
+typedef signed short     INT16, *PINT16;
+typedef signed int       INT32, *PINT32;
 typedef signed __int64   INT64, *PINT64;
-typedef unsigned __int8  UINT8, *PUINT8;
-typedef unsigned __int16 UINT16, *PUINT16;
-typedef unsigned __int32 UINT32, *PUINT32;
+typedef unsigned char    UINT8, *PUINT8;
+typedef unsigned short   UINT16, *PUINT16;
+typedef unsigned int     UINT32, *PUINT32;
 typedef unsigned __int64 UINT64, *PUINT64;
-typedef signed __int32   LONG32, *PLONG32;
-typedef unsigned __int32 ULONG32, *PULONG32;
-typedef unsigned __int32 DWORD32, *PDWORD32;
+typedef signed int       LONG32, *PLONG32;
+typedef unsigned int     ULONG32, *PULONG32;
+typedef unsigned int     DWORD32, *PDWORD32;
 typedef signed __int64   LONG64, *PLONG64;
 typedef unsigned __int64 ULONG64, *PULONG64;
 typedef unsigned __int64 DWORD64, *PDWORD64;
@@ -88,8 +88,8 @@ typedef unsigned __int64 DWORD_PTR, *PDWORD_PTR;
 #define MININT_PTR 0x8000000000000000
 #define MAXUINT_PTR 0xffffffffffffffff
 
-typedef signed __int32   HALF_PTR, *PHALF_PTR;
-typedef unsigned __int32 UHALF_PTR, *PUHALF_PTR;
+typedef int HALF_PTR, *PHALF_PTR;
+typedef unsigned int UHALF_PTR, *PUHALF_PTR;
 
 #define MAXHALF_PTR 0x7fffffff
 #define MINHALF_PTR 0x80000000
@@ -97,9 +97,9 @@ typedef unsigned __int32 UHALF_PTR, *PUHALF_PTR;
 
 #else /* FIXME: defined(_WIN32) */
 
-typedef signed __int32   INT_PTR, *PINT_PTR;
+typedef int INT_PTR, *PINT_PTR;
 typedef long LONG_PTR, *PLONG_PTR;
-typedef unsigned __int32 UINT_PTR, *PUINT_PTR;
+typedef unsigned int UINT_PTR, *PUINT_PTR;
 typedef unsigned long ULONG_PTR, *PULONG_PTR;
 typedef ULONG_PTR DWORD_PTR, *PDWORD_PTR;
 
@@ -107,8 +107,8 @@ typedef ULONG_PTR DWORD_PTR, *PDWORD_PTR;
 #define MININT_PTR 0x80000000
 #define MAXUINT_PTR 0xffffffff
 
-typedef signed __int16   HALF_PTR, *PHALF_PTR;
-typedef unsigned __int16 UHALF_PTR, *PUHALF_PTR;
+typedef signed short HALF_PTR, *PHALF_PTR;
+typedef unsigned short UHALF_PTR, *PUHALF_PTR;
 
 #define MAXUHALF_PTR 0xffff
 #define MAXHALF_PTR 0x7fff
@@ -139,7 +139,7 @@ typedef ULONG_PTR SIZE_T, *PSIZE_T;
 # define WORDS_LITTLEENDIAN
 # define BITFIELDS_LITTLEENDIAN
 # undef  ALLOW_UNALIGNED_ACCESS
-#elif !defined(RC_INVOKED)
+#elif !defined(RC_INVOKED) && !defined(__WIDL__)
 # error Unknown CPU architecture!
 #endif
 
diff --git a/include/wtypes.h b/include/wtypes.h
index 8a5e48ae060..2d71282b4a5 100644
--- a/include/wtypes.h
+++ b/include/wtypes.h
@@ -36,12 +36,6 @@ typedef float FLOAT;
 
 typedef double DOUBLE;
 
-typedef long LONG_PTR, *PLONG_PTR;
-
-typedef unsigned int UINT_PTR, *PUINT_PTR;
-
-typedef unsigned long ULONG_PTR, *PULONG_PTR;
-
 typedef void *PVOID, *LPVOID;
 
 typedef char CHAR;
@@ -579,31 +573,6 @@ unsigned char * __RPC_USER HMETAFILEPICT_UserMarshal  (unsigned long *, unsigned
 unsigned char * __RPC_USER HMETAFILEPICT_UserUnmarshal(unsigned long *, unsigned char *, HMETAFILEPICT *);
 void            __RPC_USER HMETAFILEPICT_UserFree     (unsigned long *, HMETAFILEPICT *);
 
-#ifndef GUID_DEFINED
-#define GUID_DEFINED
-typedef struct _GUID {
-    DWORD Data1;
-    WORD Data2;
-    WORD Data3;
-    BYTE Data4[8];
-} GUID;
-
-#endif
-#if 0 /* guiddef.h */
-typedef GUID *LPGUID;
-
-typedef GUID IID;
-
-typedef IID *LPIID;
-
-typedef GUID CLSID;
-
-typedef CLSID *LPCLSID;
-
-typedef GUID FMTID;
-
-typedef FMTID *LPFMTID;
-
 #if 0
 typedef GUID *REFGUID;
 
@@ -614,7 +583,6 @@ typedef CLSID *REFCLSID;
 typedef FMTID *REFFMTID;
 
 #endif
-#endif /* guiddef.h */
 typedef enum tagDVASPECT {
     DVASPECT_CONTENT = 1,
     DVASPECT_THUMBNAIL = 2,
diff --git a/include/wtypes.idl b/include/wtypes.idl
index 2c6fbe8b564..e43a310cfc2 100644
--- a/include/wtypes.idl
+++ b/include/wtypes.idl
@@ -18,19 +18,18 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+import "basetsd.h";
+import "guiddef.h";
+
 [
   uuid(D3980A60-910C-1068-9341-00DD010F2F1C),
   version(0.1),
   pointer_default(unique)
 ]
+
 interface IWinTypes
 {
 
-/******************** WINE STUFF ********************/
-
-cpp_quote("#include \"basetsd.h\"")
-cpp_quote("#include \"guiddef.h\"")
-
 /******************** BASIC WIN32 TYPES ********************/
 cpp_quote("#if 0 /* winnt.h */") /* don't redefine these */
 
@@ -48,11 +47,6 @@ typedef unsigned long ULONG;
 typedef float FLOAT;
 typedef double DOUBLE;
 
-/* FIXME: This is wrong for WIN64 */
-typedef long LONG_PTR, *PLONG_PTR;
-typedef unsigned int UINT_PTR, *PUINT_PTR;
-typedef unsigned long ULONG_PTR, *PULONG_PTR;
-
 typedef void *PVOID, *LPVOID;
 
 typedef char CHAR;
@@ -533,28 +527,6 @@ DECLARE_WIREM_HANDLE(HMETAFILEPICT);
 
 /******************** GUID TYPES ********************/
 
-cpp_quote("#ifndef GUID_DEFINED")
-cpp_quote("#define GUID_DEFINED")
-typedef struct _GUID {
-  DWORD Data1;
-  WORD  Data2;
-  WORD  Data3;
-  BYTE  Data4[8];
-} GUID;
-cpp_quote("#endif")
-
-cpp_quote("#if 0 /* guiddef.h */")
-typedef GUID *LPGUID;
-
-typedef GUID IID;
-typedef IID *LPIID;
-
-typedef GUID CLSID;
-typedef CLSID *LPCLSID;
-
-typedef GUID FMTID;
-typedef FMTID *LPFMTID;
-
 cpp_quote("#if 0") /* for IDL only (C/C++ defs are in guiddef.h) */
 typedef GUID *REFGUID;
 typedef IID *REFIID;
@@ -562,8 +534,6 @@ typedef CLSID *REFCLSID;
 typedef FMTID *REFFMTID;
 cpp_quote("#endif")
 
-cpp_quote("#endif /* guiddef.h */")
-
 /******************** MISC TYPES ********************/
 
 typedef enum tagDVASPECT {