diff --git a/extmod/vfs_posix.c b/extmod/vfs_posix.c
index ed4c06e367..7b1fa3a806 100644
--- a/extmod/vfs_posix.c
+++ b/extmod/vfs_posix.c
@@ -23,6 +23,9 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+#ifdef _WIN32
+#include "ports/windows/windows_version.h"
+#endif
 
 #include "py/runtime.h"
 #include "py/mperrno.h"
diff --git a/ports/windows/init.c b/ports/windows/init.c
index 87d581c304..b23643cf28 100644
--- a/ports/windows/init.c
+++ b/ports/windows/init.c
@@ -24,6 +24,8 @@
  * THE SOFTWARE.
  */
 
+#include "windows_version.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <windows.h>
diff --git a/ports/windows/windows_mphal.c b/ports/windows/windows_mphal.c
index b636393f54..f663016534 100644
--- a/ports/windows/windows_mphal.c
+++ b/ports/windows/windows_mphal.c
@@ -24,6 +24,7 @@
  * THE SOFTWARE.
  */
 
+#include "windows_version.h"
 
 #include "py/runtime.h"
 #include "py/mphal.h"
diff --git a/ports/windows/windows_version.h b/ports/windows/windows_version.h
new file mode 100644
index 0000000000..ee4317a89f
--- /dev/null
+++ b/ports/windows/windows_version.h
@@ -0,0 +1,48 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013, 2014 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef MICROPY_INCLUDED_WINDOWS_VERSION_H
+#define MICROPY_INCLUDED_WINDOWS_VERSION_H
+
+// This file defines various macros, that are used by windows.h to
+// decide what to define.
+//
+// Any file that is going to include windows.h should include this file first.
+//
+// This is in a central header, because it's likely that the supported
+// Windows version number will need increasing in future, as new versions
+// of Windows are released and old versions drop out of support.  Putting
+// it in a central place means there is only one place to update it.
+// It also means that it is consistent across all files in the project.
+
+// We want all APIs that were supported in Windows 8.
+#define WINVER 0x0602
+#define _WIN32_WINNT 0x0602
+
+// Don't include WinSock 1 APIs.
+// This is required for WinSock 2 to work.
+#define WIN32_LEAN_AND_MEAN
+
+#endif // MICROPY_INCLUDED_WINDOWS_VERSION_H