Trying to make sync client with ssl stream show other flaw in error handling asio/ssl/detail/openssl_operation.hpp int sync_user_handler(const boost::asio::error& error, int rc) { if (!error) return rc; throw error; } throw errors even if used asio::assing_error forcing to use followng code boost::asio::error error_; try { _connection->socket().shutdown(boost::asio::assign_error(error_)); } catch (const boost::asio::error&) { } If anyone know some workaround or hotfixes pls let me know P.S. Thanks for great library