Pytest treating warning as exception

I’m running pytest with:
python -m pytest tests/ -vv -rsx

However, it is treating warnings as errors:

_______________ ERROR collecting tests/test_synthesis_report.py ________________
tests/test_synthesis_report.py:6: in <module>
    import synthesis_report
synthesis_report.py:3: in <module>
    from lib import cmdLineArgs, varsModule
lib/varsModule.py:6: in <module>
    import imp
venv/lib/python3.7/imp.py:33: in <module>
    DeprecationWarning, stacklevel=2)
E   DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses

How do I make it not do this?

This might be a better question for the pytest community itself: https://docs.pytest.org/en/latest/contact.html