pytest watch seems to fail when pyproject.toml is used as a config file

When pytest config is stored in pyproject.toml:

Traceback (most recent call last):
  File "/Users/maximilian/Library/Caches/pypoetry/virtualenvs/n-cyukv0jK-py3.8/bin/ptw", line 8, in <module>
    sys.exit(main())
  File "/Users/maximilian/Library/Caches/pypoetry/virtualenvs/n-cyukv0jK-py3.8/lib/python3.8/site-packages/pytest_watch/command.py", line 83, in main
    if not merge_config(args, pytest_args, verbose=args['--verbose']):
  File "/Users/maximilian/Library/Caches/pypoetry/virtualenvs/n-cyukv0jK-py3.8/lib/python3.8/site-packages/pytest_watch/config.py", line 95, in merge_config
    config.read(config_path)
  File "/usr/local/Cellar/python@3.8/3.8.5/Frameworks/Python.framework/Versions/3.8/lib/python3.8/configparser.py", line 697, in read
    self._read(fp, filename)
  File "/usr/local/Cellar/python@3.8/3.8.5/Frameworks/Python.framework/Versions/3.8/lib/python3.8/configparser.py", line 1113, in _read
    raise e
configparser.ParsingError: Source contains parsing errors: '/Users/maximilian/workspace/n/pyproject.toml'
	[line 59]: ']\n'

This works when the pytest config in pyproject.toml is removed