diff --git a/libs/fst/00_PATCH_win_io.patch b/libs/fst/00_PATCH_win_io.patch
index 1105538e5..bf8679406 100644
--- a/libs/fst/00_PATCH_win_io.patch
+++ b/libs/fst/00_PATCH_win_io.patch
@@ -20,6 +20,15 @@
  #define WIN32_LEAN_AND_MEAN
  #include <windows.h>
  #endif
+@@ -137,7 +137,7 @@ void **JenkinsIns(void *base_i, const unsigned char *mem, uint32_t length, uint3
+ #include <sys/sysctl.h>
+ #endif
+ 
+-#if defined(FST_MACOSX) || defined(__MINGW32__) || defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__NetBSD__)
++#if defined(FST_MACOSX) || defined(__MINGW32__) || defined(_MSC_VER) || defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__NetBSD__)
+ #define FST_UNBUFFERED_IO
+ #endif
+ 
 @@ -159,7 +159,7 @@ void **JenkinsIns(void *base_i, const unsigned char *mem, uint32_t length, uint3
  /***                 ***/
  /***********************/
@@ -38,3 +47,12 @@
  #include <limits.h>
  #define fstMmap(__addr,__len,__prot,__flags,__fd,__off) fstMmap2((__len), (__fd), (__off))
  #define fstMunmap(__addr,__len)                         UnmapViewOfFile((LPCVOID)__addr)
+@@ -4638,7 +4638,7 @@ if(sectype == FST_BL_ZWRAPPER)
+ #endif
+ 
+         fstReaderFseeko(xc, xc->f, FST_ZWRAPPER_HDR_SIZE, SEEK_SET);
+-#ifndef __MINGW32__
++#if !defined(__MINGW32__) && !defined(_MSC_VER)
+         fflush(xc->f);
+ #else
+ 	/* Windows UCRT runtime library reads one byte ahead in the file
diff --git a/libs/fst/fstapi.cc b/libs/fst/fstapi.cc
index 00a304909..74e755d31 100644
--- a/libs/fst/fstapi.cc
+++ b/libs/fst/fstapi.cc
@@ -137,7 +137,7 @@ void **JenkinsIns(void *base_i, const unsigned char *mem, uint32_t length, uint3
 #include <sys/sysctl.h>
 #endif
 
-#if defined(FST_MACOSX) || defined(__MINGW32__) || defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__NetBSD__)
+#if defined(FST_MACOSX) || defined(__MINGW32__) || defined(_MSC_VER) || defined(__OpenBSD__) || defined(__FreeBSD__) || defined(__NetBSD__)
 #define FST_UNBUFFERED_IO
 #endif
 
@@ -4638,7 +4638,7 @@ if(sectype == FST_BL_ZWRAPPER)
 #endif
 
         fstReaderFseeko(xc, xc->f, FST_ZWRAPPER_HDR_SIZE, SEEK_SET);
-#ifndef __MINGW32__
+#if !defined(__MINGW32__) && !defined(_MSC_VER)
         fflush(xc->f);
 #else
 	/* Windows UCRT runtime library reads one byte ahead in the file