diff --git a/reactos/include/psdk/basetsd.h b/reactos/include/psdk/basetsd.h
index e2e5b93f453..929475d5336 100644
--- a/reactos/include/psdk/basetsd.h
+++ b/reactos/include/psdk/basetsd.h
@@ -79,33 +79,33 @@ typedef unsigned int UHALF_PTR, *PUHALF_PTR;
 typedef int HALF_PTR, *PHALF_PTR;
 
 #if !defined(__midl) && !defined(__WIDL__)
-static inline unsigned long HandleToUlong(const void* h )
+static __inline unsigned long HandleToUlong(const void* h )
     { return((unsigned long)(ULONG_PTR) h ); }
-static inline long HandleToLong( const void* h )
+static __inline long HandleToLong( const void* h )
     { return((long)(LONG_PTR) h ); }
-static inline void* ULongToHandle( const long h )
+static __inline void* ULongToHandle( const long h )
     { return((void*) (UINT_PTR) h ); }
-static inline void* LongToHandle( const long h )
+static __inline void* LongToHandle( const long h )
     { return((void*) (INT_PTR) h ); }
-static inline unsigned long PtrToUlong( const void* p)
+static __inline unsigned long PtrToUlong( const void* p)
     { return((unsigned long)(ULONG_PTR) p ); }
-static inline unsigned int PtrToUint( const void* p )
+static __inline unsigned int PtrToUint( const void* p )
     { return((unsigned int)(UINT_PTR) p ); }
-static inline unsigned short PtrToUshort( const void* p )
+static __inline unsigned short PtrToUshort( const void* p )
     { return((unsigned short)(ULONG_PTR) p ); }
-static inline long PtrToLong( const void* p )
+static __inline long PtrToLong( const void* p )
     { return((long)(LONG_PTR) p ); }
-static inline int PtrToInt( const void* p )
+static __inline int PtrToInt( const void* p )
     { return((int)(INT_PTR) p ); }
-static inline short PtrToShort( const void* p )
+static __inline short PtrToShort( const void* p )
     { return((short)(INT_PTR) p ); }
-static inline void* IntToPtr( const int i )
+static __inline void* IntToPtr( const int i )
     { return( (void*)(INT_PTR)i ); }
-static inline void* UIntToPtr(const unsigned int ui)
+static __inline void* UIntToPtr(const unsigned int ui)
     { return( (void*)(UINT_PTR)ui ); }
-static inline void* LongToPtr( const long l )
+static __inline void* LongToPtr( const long l )
     { return( (void*)(LONG_PTR)l ); }
-static inline void* ULongToPtr( const unsigned long ul )
+static __inline void* ULongToPtr( const unsigned long ul )
     { return( (void*)(ULONG_PTR)ul ); }
 #endif /* !__midl */
 #else /*  !_WIN64 */