diff --git a/include/boost/function/detail/prologue.hpp b/include/boost/function/detail/prologue.hpp
index 2af12b8..b0303fd 100644
--- a/include/boost/function/detail/prologue.hpp
+++ b/include/boost/function/detail/prologue.hpp
@@ -9,7 +9,6 @@
 
 #ifndef BOOST_FUNCTION_PROLOGUE_HPP
 #define BOOST_FUNCTION_PROLOGUE_HPP
-#  include <boost/function/detail/requires_cxx11.hpp>
 #  include <boost/function/function_base.hpp>
 #  include <boost/mem_fn.hpp>
 #  include <boost/throw_exception.hpp>
diff --git a/include/boost/function/detail/requires_cxx11.hpp b/include/boost/function/detail/requires_cxx11.hpp
deleted file mode 100644
index 8ed947c..0000000
--- a/include/boost/function/detail/requires_cxx11.hpp
+++ /dev/null
@@ -1,22 +0,0 @@
-#ifndef BOOST_FUNCTION_DETAIL_REQUIRES_CXX11_HPP_INCLUDED
-#define BOOST_FUNCTION_DETAIL_REQUIRES_CXX11_HPP_INCLUDED
-
-// Copyright 2023 Peter Dimov
-// Distributed under the Boost Software License, Version 1.0.
-// https://www.boost.org/LICENSE_1_0.txt
-
-#include <boost/config.hpp>
-#include <boost/config/pragma_message.hpp>
-
-#if defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) || \
-    defined(BOOST_NO_CXX11_RVALUE_REFERENCES) || \
-    defined(BOOST_NO_CXX11_DECLTYPE) || \
-    defined(BOOST_NO_CXX11_CONSTEXPR) || \
-    defined(BOOST_NO_CXX11_NOEXCEPT) || \
-    defined(BOOST_NO_CXX11_HDR_FUNCTIONAL)
-
-BOOST_PRAGMA_MESSAGE("C++03 support was deprecated in Boost.Function 1.82 and will be removed in Boost.Function 1.85.")
-
-#endif
-
-#endif // #ifndef BOOST_FUNCTION_DETAIL_REQUIRES_CXX11_HPP_INCLUDED