diff --git a/compat/mingw.c b/compat/mingw.c
index 34ee427bafad4f..6b5b5b2c7011a8 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -3,6 +3,8 @@
 #include <conio.h>
 #include "../strbuf.h"
 
+#include <shellapi.h>
+
 static int err_win_to_posix(DWORD winerr)
 {
 	int error = ENOSYS;
diff --git a/compat/mingw.h b/compat/mingw.h
index bcd23b0a457037..5b5258bcebbbea 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -41,6 +41,7 @@ struct passwd {
 
 extern char *getpass(const char *prompt);
 
+#ifndef POLLIN
 struct pollfd {
 	int fd;           /* file descriptor */
 	short events;     /* requested events */
@@ -48,6 +49,7 @@ struct pollfd {
 };
 #define POLLIN 1
 #define POLLHUP 2
+#endif
 
 typedef void (__cdecl *sig_handler_t)(int);
 struct sigaction {
diff --git a/compat/msvc.h b/compat/msvc.h
index 6daf313e8c83e8..53a6d30c02597b 100644
--- a/compat/msvc.h
+++ b/compat/msvc.h
@@ -1,13 +1,6 @@
 #ifndef __MSVC__HEAD
 #define __MSVC__HEAD
 
-/* Define minimize windows version */
-#define WINVER 0x0500
-#define _WIN32_WINNT 0x0500
-#define _WIN32_WINDOWS 0x0410
-#define _WIN32_IE 0x0700
-#define NTDDI_VERSION NTDDI_WIN2KSP1
-#include <winsock2.h>
 #include <direct.h>
 #include <process.h>
 #include <malloc.h>
diff --git a/compat/win32.h b/compat/win32.h
index e8c178d8cdc9e2..8ce91048deffc1 100644
--- a/compat/win32.h
+++ b/compat/win32.h
@@ -2,7 +2,9 @@
 #define WIN32_H
 
 /* common Win32 functions for MinGW and Cygwin */
+#ifndef WIN32         /* Not defined by Cygwin */
 #include <windows.h>
+#endif
 
 static inline int file_attr_to_st_mode (DWORD attr)
 {
diff --git a/compat/winansi.c b/compat/winansi.c
index 9217c24b43f754..dedce2104eaf5c 100644
--- a/compat/winansi.c
+++ b/compat/winansi.c
@@ -2,7 +2,6 @@
  * Copyright 2008 Peter Harris <git@peter.is-a-geek.org>
  */
 
-#include <windows.h>
 #include "../git-compat-util.h"
 
 /*
diff --git a/git-compat-util.h b/git-compat-util.h
index 8ea444fdc01c79..8d6e29cdeadfe1 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -65,6 +65,12 @@
 #define _NETBSD_SOURCE 1
 #define _SGI_SOURCE 1
 
+#ifdef WIN32 /* Both MinGW and MSVC */
+#define WIN32_LEAN_AND_MEAN  /* stops windows.h including winsock.h */
+#include <winsock2.h>
+#include <windows.h>
+#endif
+
 #include <unistd.h>
 #include <stdio.h>
 #include <sys/stat.h>
diff --git a/thread-utils.c b/thread-utils.c
index 55e7e2904eb5f9..4f9c829c2df319 100644
--- a/thread-utils.c
+++ b/thread-utils.c
@@ -1,9 +1,6 @@
 #include "cache.h"
 
-#ifdef _WIN32
-#  define WIN32_LEAN_AND_MEAN
-#  include <windows.h>
-#elif defined(hpux) || defined(__hpux) || defined(_hpux)
+#if defined(hpux) || defined(__hpux) || defined(_hpux)
 #  include <sys/pstat.h>
 #endif