diff --git a/plugin/fugitive.vim b/plugin/fugitive.vim
index 84ae2d0..f334e36 100644
--- a/plugin/fugitive.vim
+++ b/plugin/fugitive.vim
@@ -1652,7 +1652,11 @@ function! s:ReplaceCmd(cmd,...) abort
         let prefix = 'env GIT_INDEX_FILE='.s:shellesc(a:1).' '
       endif
     endif
-    call writefile(split(system(prefix.a:cmd), "\n", 1), tmp, 'b')
+    if &shell =~# 'cmd'
+      call system('cmd /c "'.prefix.a:cmd.' > '.tmp.'"')
+    else
+      call system(' ('.prefix.a:cmd.' > '.tmp.') ')
+    endif
   finally
     if exists('old_index')
       let $GIT_INDEX_FILE = old_index