diff --git a/include/athena/FileReader.hpp b/include/athena/FileReader.hpp
index feefc09..54b7382 100644
--- a/include/athena/FileReader.hpp
+++ b/include/athena/FileReader.hpp
@@ -1,14 +1,6 @@
 #pragma once
 
-#if _WIN32
-#ifndef WIN32_LEAN_AND_MEAN
-#define WIN32_LEAN_AND_MEAN
-#endif
-#include <windows.h>
-#else
 #include <cstdio>
-#endif
-
 #include <memory>
 #include <string>
 
@@ -49,7 +41,7 @@ public:
   void setCacheSize(const atInt32 blockSize);
 
 #if _WIN32
-  using HandleType = HANDLE;
+  using HandleType = void*;
 #else
   using HandleType = FILE*;
 #endif
diff --git a/include/athena/FileWriter.hpp b/include/athena/FileWriter.hpp
index a8dcfbf..66dcd90 100644
--- a/include/athena/FileWriter.hpp
+++ b/include/athena/FileWriter.hpp
@@ -1,13 +1,6 @@
 #pragma once
 
-#ifdef _WIN32
-#ifndef WIN32_LEAN_AND_MEAN
-#define WIN32_LEAN_AND_MEAN
-#endif
-#include <windows.h>
-#else
 #include <cstdio>
-#endif
 
 #include "athena/IStreamWriter.hpp"
 #include "athena/Types.hpp"
@@ -43,7 +36,7 @@ public:
   void writeUBytes(const atUint8* data, atUint64 len) override;
 
 #ifdef _WIN32
-  using HandleType = HANDLE;
+  using HandleType = void*;
 #else
   using HandleType = FILE*;
 #endif
diff --git a/src/athena/FileReaderWin32.cpp b/src/athena/FileReaderWin32.cpp
index 70f7a70..af4d867 100644
--- a/src/athena/FileReaderWin32.cpp
+++ b/src/athena/FileReaderWin32.cpp
@@ -1,4 +1,10 @@
 #include "athena/FileReader.hpp"
+
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+#include <windows.h>
+
 #include "win32_largefilewrapper.h"
 
 namespace athena::io {
diff --git a/src/athena/FileWriterWin32.cpp b/src/athena/FileWriterWin32.cpp
index 7e1c912..cd095c0 100644
--- a/src/athena/FileWriterWin32.cpp
+++ b/src/athena/FileWriterWin32.cpp
@@ -1,5 +1,9 @@
 #include "athena/FileWriter.hpp"
 
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+#include <windows.h>
 #include <algorithm>
 #include <limits>