diff --git a/thirdparty/patches/msgpack-windows-iovec.patch b/thirdparty/patches/msgpack-windows-iovec.patch
index b4e9261d9..4d961d2be 100644
--- a/thirdparty/patches/msgpack-windows-iovec.patch
+++ b/thirdparty/patches/msgpack-windows-iovec.patch
@@ -1,11 +1,8 @@
 diff --git include/msgpack/v1/vrefbuffer.hpp include/msgpack/v1/vrefbuffer.hpp
 --- include/msgpack/v1/vrefbuffer.hpp
 +++ include/msgpack/v1/vrefbuffer.hpp
-@@ -28,4 +28,12 @@
--struct iovec {
--    void  *iov_base;
--    size_t iov_len;
--};
+@@ -28,4 +28,19 @@
++#ifdef _WIN32
 +#ifndef _WS2DEF_
 +#include <Winsock2.h>
 +#endif
@@ -18,6 +15,12 @@ diff --git include/msgpack/v1/vrefbuffer.hpp include/msgpack/v1/vrefbuffer.hpp
 +#ifndef iov_len
 +#define iov_len len
 +#endif
++#else
+ struct iovec {
+     void  *iov_base;
+     size_t iov_len;
+ };
++#endif
 @@ -171,1 +179,1 @@
 -                const_cast<const void *>((m_tail - 1)->iov_base)
 +                (m_tail - 1)->iov_base