Hello, I've noticed that WaitHandler can be called after boost::asio::deadline_timer destruction. It may cause using of uninitialized data. Are there any other solutions of graceful destruction of boost::asio::deadline_timer to be sure that after this destruction WaitHandler will never be called? Example pseudo code: class UsingDeadlineTimer { char some_data_accessed_from_the_wait_handler[512]; boost::asio::deadline_timer timer; void WaitHandler(const boost::system::error_code &ec) { if(ec == boost::asio::error::operation_aborted) { return; } memset(some_data_accessed_from_the_wait_handler, 'E', 512); // cause the problem, because UsingDeadlineTimer may be already destroyed. } UsingDeadlineTimer() : timer(io_service) { timer.expires_at(the moment of UsingDeadlineTimer destruction); timer.async_wait( boost::bind(&UsingDeadlineTimer::WaitHandler, this, boost::asio::placeholders::error) ); } ~UsingDeadlineTimer() { timer.cancel(); // but we already can be in the WaitHandler body which will access some_data_accessed_from_the_wait_handler } }; Thank you, Daniel