diff --git a/include/boost/beast/http/impl/file_body_win32.hpp b/include/boost/beast/http/impl/file_body_win32.hpp
index cba7a0ed..e798a7b6 100644
--- a/include/boost/beast/http/impl/file_body_win32.hpp
+++ b/include/boost/beast/http/impl/file_body_win32.hpp
@@ -434,7 +434,7 @@ public:
             static_cast<boost::winapi::DWORD_>(
             (std::min<std::uint64_t>)(
                 (std::min<std::uint64_t>)(w.body_.last_ - w.pos_, sr_.limit()),
-                (std::numeric_limits<boost::winapi::DWORD_>::max)()));
+                (std::numeric_limits<boost::winapi::INT_>::max)() - 1));
         net::windows::overlapped_ptr overlapped{
             sock_.get_executor(), std::move(*this)};
         // Note that we have moved *this, so we cannot access
@@ -562,7 +562,7 @@ write_some(
         static_cast<boost::winapi::DWORD_>(
         (std::min<std::uint64_t>)(
             (std::min<std::uint64_t>)(w.body_.last_ - w.pos_, sr.limit()),
-            (std::numeric_limits<boost::winapi::DWORD_>::max)()));
+            (std::numeric_limits<boost::winapi::INT_>::max)() - 1));
     auto const bSuccess = ::TransmitFile(
         sock.native_handle(),
         w.body_.file_.native_handle(),