Add some missing definitions for mingw.org these shouldn't be necessary if _WIN32_WINNT >= _WIN32_WINNT_VISTA
diff --git a/src/win32/mingw-compat.h b/src/win32/mingw-compat.h
index feedfec..a4a5a31 100644
--- a/src/win32/mingw-compat.h
+++ b/src/win32/mingw-compat.h
@@ -17,6 +17,13 @@
#define stat _stati64
#endif
+#if _WIN32_WINNT < 0x0600 && !defined(__MINGW64_VERSION_MAJOR)
+#undef MemoryBarrier
+void __mingworg_MemoryBarrier(void);
+#define MemoryBarrier __mingworg_MemoryBarrier
+#define VOLUME_NAME_DOS 0x0
+#endif
+
#endif
#endif /* INCLUDE_mingw_compat__ */