How to show warnings in py.test

I just ran py.test on my code and got the following output:

================== 6 passed, 2 pytest-warnings in 40.79 seconds =======================

However, I cannot see what py.test would like to warn me about. How can I turn on warning output to the console?

py.test --help offers me the --strict flag:

--strict run pytest in strict mode, warnings become errors.

However I just want to see the output, not make my tests fail.

I checked pytest.org and this question but they are only concerned with asserting warnings in python, not showing warnings generated on the commandline.