diff --git a/include/boost/system/detail/config.hpp b/include/boost/system/detail/config.hpp
index 422002bc..5ec2914d 100644
--- a/include/boost/system/detail/config.hpp
+++ b/include/boost/system/detail/config.hpp
@@ -8,7 +8,6 @@
 //
 // See http://www.boost.org/libs/system for documentation.
 
-#include <boost/system/detail/requires_cxx11.hpp>
 #include <boost/config.hpp>
 #include <boost/config/workaround.hpp>
 
diff --git a/include/boost/system/detail/requires_cxx11.hpp b/include/boost/system/detail/requires_cxx11.hpp
deleted file mode 100644
index 016791c0..00000000
--- a/include/boost/system/detail/requires_cxx11.hpp
+++ /dev/null
@@ -1,21 +0,0 @@
-#ifndef BOOST_SYSTEM_DETAIL_REQUIRES_CXX11_HPP_INCLUDED
-#define BOOST_SYSTEM_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_CONSTEXPR) || \
-    defined(BOOST_NO_CXX11_NOEXCEPT) || \
-    defined(BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS) || \
-    defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS) || \
-    defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
-
-BOOST_PRAGMA_MESSAGE("C++03 support was deprecated in Boost.System 1.82 and will be removed in Boost.System 1.85.")
-
-#endif
-
-#endif // #ifndef BOOST_SYSTEM_DETAIL_REQUIRES_CXX11_HPP_INCLUDED