diff --git a/cli/xsum_os_specific.c b/cli/xsum_os_specific.c
index aa6cb834..8438d0cf 100644
--- a/cli/xsum_os_specific.c
+++ b/cli/xsum_os_specific.c
@@ -79,7 +79,7 @@ static int XSUM_IS_CONSOLE(FILE* stdStream)
 #elif defined(MSDOS) || defined(OS2)
 #  include <io.h>       /* _isatty */
 #  define XSUM_IS_CONSOLE(stdStream) _isatty(_fileno(stdStream))
-#elif defined(WIN32) || defined(_WIN32)
+#elif defined(_WIN32)
 #  include <io.h>      /* _isatty */
 #  include <windows.h> /* DeviceIoControl, HANDLE, FSCTL_SET_SPARSE */
 #  include <stdio.h>   /* FILE */
@@ -92,7 +92,7 @@ static __inline int XSUM_IS_CONSOLE(FILE* stdStream)
 #  define XSUM_IS_CONSOLE(stdStream) 0
 #endif
 
-#if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(_WIN32)
+#if defined(MSDOS) || defined(OS2) || defined(_WIN32)
 #  include <fcntl.h>   /* _O_BINARY */
 #  include <io.h>      /* _setmode, _fileno, _get_osfhandle */
 #  if !defined(__DJGPP__)
diff --git a/xxhash.h b/xxhash.h
index ee1bcdff..4f1edf16 100644
--- a/xxhash.h
+++ b/xxhash.h
@@ -445,7 +445,7 @@ extern "C" {
 
 /*! @brief Marks a global symbol. */
 #if !defined(XXH_INLINE_ALL) && !defined(XXH_PRIVATE_API)
-#  if defined(WIN32) && defined(_MSC_VER) && (defined(XXH_IMPORT) || defined(XXH_EXPORT))
+#  if defined(_WIN32) && defined(_MSC_VER) && (defined(XXH_IMPORT) || defined(XXH_EXPORT))
 #    ifdef XXH_EXPORT
 #      define XXH_PUBLIC_API __declspec(dllexport)
 #    elif XXH_IMPORT
@@ -521,7 +521,7 @@ extern "C" {
 
 /* specific declaration modes for Windows */
 #if !defined(XXH_INLINE_ALL) && !defined(XXH_PRIVATE_API)
-#  if defined(WIN32) && defined(_MSC_VER) && (defined(XXH_IMPORT) || defined(XXH_EXPORT))
+#  if defined(_WIN32) && defined(_MSC_VER) && (defined(XXH_IMPORT) || defined(XXH_EXPORT))
 #    ifdef XXH_EXPORT
 #      define XXH_PUBLIC_API __declspec(dllexport)
 #    elif XXH_IMPORT