<!-- Thanks for wanting to report an issue you've found in uvloop. Please fill in the template below. It will be much easier for us to fix the issue if a test case that reproduces the problem is provided, with clear instructions on how to run it. Thank you! --> * **uvloop version**: uvloop==0.16.0 * **Python version**: 3.10.4 * **Platform**: Linux-5.17.5-200.fc35.x86_64-x86_64-with-glibc2.34 * **Can you reproduce the bug with `PYTHONASYNCIODEBUG` in env?**: Yes * **Does uvloop behave differently from vanilla asyncio? How?**: It segfaults. <!-- Enter your issue details below this comment. --> Calling when() on a TimerHandle object after callback has been executed causes a core dump. ```python import uvloop import asyncio async def main(): loop = asyncio.get_running_loop() timer = loop.call_later(0.1, lambda: None) # call any function await asyncio.sleep(0.2) timer.when() # segfault happens here uvloop.install() asyncio.run(main())