diff --git a/include/libssh2.h b/include/libssh2.h
index e4e12613..f9526760 100644
--- a/include/libssh2.h
+++ b/include/libssh2.h
@@ -90,11 +90,7 @@
 extern "C" {
 #endif
 
-#if defined(_WIN32) || defined(WIN32)
-#define LIBSSH2_WIN32
-#endif
-
-#ifdef LIBSSH2_WIN32
+#ifdef _WIN32
 # include <basetsd.h>
 # include <winsock2.h>
 #endif
@@ -106,7 +102,7 @@ extern "C" {
 
 /* Allow alternate API prefix from CFLAGS or calling app */
 #ifndef LIBSSH2_API
-# ifdef LIBSSH2_WIN32
+# ifdef _WIN32
 #  if defined(LIBSSH2_EXPORTS) || defined(_WINDLL)
 #   ifdef LIBSSH2_LIBRARY
 #    define LIBSSH2_API __declspec(dllexport)
@@ -116,9 +112,9 @@ extern "C" {
 #  else
 #   define LIBSSH2_API
 #  endif
-# else /* !LIBSSH2_WIN32 */
+# else /* !_WIN32 */
 #  define LIBSSH2_API
-# endif /* LIBSSH2_WIN32 */
+# endif /* _WIN32 */
 #endif /* LIBSSH2_API */
 
 #ifdef HAVE_SYS_UIO_H
@@ -144,13 +140,13 @@ typedef unsigned long long libssh2_uint64_t;
 typedef long long libssh2_int64_t;
 #endif
 
-#ifdef LIBSSH2_WIN32
+#ifdef _WIN32
 typedef SOCKET libssh2_socket_t;
 #define LIBSSH2_INVALID_SOCKET INVALID_SOCKET
-#else /* !LIBSSH2_WIN32 */
+#else /* !_WIN32 */
 typedef int libssh2_socket_t;
 #define LIBSSH2_INVALID_SOCKET -1
-#endif /* LIBSSH2_WIN32 */
+#endif /* _WIN32 */
 
 /*
  * Determine whether there is small or large file support on windows.
@@ -176,7 +172,7 @@ typedef int libssh2_socket_t;
 #  undef LIBSSH2_USE_WIN32_LARGE_FILES
 #endif
 
-#if defined(LIBSSH2_WIN32) && !defined(LIBSSH2_USE_WIN32_LARGE_FILES) && \
+#if defined(_WIN32) && !defined(LIBSSH2_USE_WIN32_LARGE_FILES) && \
     !defined(LIBSSH2_USE_WIN32_SMALL_FILES)
 #  define LIBSSH2_USE_WIN32_SMALL_FILES
 #endif
diff --git a/include/libssh2_sftp.h b/include/libssh2_sftp.h
index 8b41f1d7..9d7a8fbb 100644
--- a/include/libssh2_sftp.h
+++ b/include/libssh2_sftp.h
@@ -42,7 +42,7 @@
 
 #include "libssh2.h"
 
-#ifndef LIBSSH2_WIN32
+#ifndef _WIN32
 #include <unistd.h>
 #endif