diff --git a/simplecpp.cpp b/simplecpp.cpp
index b1505cb6..4d64d582 100644
--- a/simplecpp.cpp
+++ b/simplecpp.cpp
@@ -3,15 +3,22 @@
  * Copyright (C) 2016-2023 simplecpp team
  */
 
-#if defined(_WIN32) || defined(__CYGWIN__) || defined(__MINGW32__)
-#  define _WIN32_WINNT 0x0602
+#if defined(_WIN32)
+#  ifndef _WIN32_WINNT
+#    define _WIN32_WINNT 0x0602
+#  endif
 #  define NOMINMAX
+#  define WIN32_LEAN_AND_MEAN
 #  include <windows.h>
 #  undef ERROR
 #endif
 
 #include "simplecpp.h"
 
+#if defined(_WIN32) || defined(__CYGWIN__) || defined(__MINGW32__)
+#  define SIMPLECPP_WINDOWS
+#endif
+
 #include <algorithm>
 #include <cassert>
 #include <cctype>
@@ -3082,7 +3089,7 @@ std::pair<simplecpp::FileData *, bool> simplecpp::FileDataCache::get(const std::
 
 bool simplecpp::FileDataCache::getFileId(const std::string &path, FileID &id)
 {
-#ifdef SIMPLECPP_WINDOWS
+#ifdef _WIN32
     HANDLE hFile = CreateFileA(path.c_str(), 0, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
 
     if (hFile == INVALID_HANDLE_VALUE)
diff --git a/simplecpp.h b/simplecpp.h
index 43a03730..ef748b3e 100644
--- a/simplecpp.h
+++ b/simplecpp.h
@@ -6,10 +6,6 @@
 #ifndef simplecppH
 #define simplecppH
 
-#if defined(_WIN32) || defined(__CYGWIN__) || defined(__MINGW32__)
-#  define SIMPLECPP_WINDOWS
-#endif
-
 #include <cctype>
 #include <cstring>
 #include <iosfwd>
@@ -43,7 +39,7 @@
 #  define SIMPLECPP_LIB
 #endif
 
-#ifdef SIMPLECPP_WINDOWS
+#ifdef _WIN32
 #  include <cstdint>
 #else
 #  include <sys/stat.h>
@@ -471,7 +467,7 @@ namespace simplecpp {
 
     private:
         struct FileID {
-#ifdef SIMPLECPP_WINDOWS
+#ifdef _WIN32
             struct {
                 std::uint64_t VolumeSerialNumber;
                 struct {
@@ -495,7 +491,7 @@ namespace simplecpp {
 #endif
             struct Hasher {
                 std::size_t operator()(const FileID &id) const {
-#ifdef SIMPLECPP_WINDOWS
+#ifdef _WIN32
                     return static_cast<std::size_t>(id.fileIdInfo.FileId.IdentifierHi ^ id.fileIdInfo.FileId.IdentifierLo ^
                                                     id.fileIdInfo.VolumeSerialNumber);
 #else