Django run systemcheck as unittest

I was doing some refactoring and ran into the case where all my unit tests passed when running manage.py test <app_name>. However, when I went to run a custom admin command I got a SystemCheckError and running manage.py check raises the same error.

I'm surprised that the test framework does not run the System Check by default. What is the best way to run SystemCheck during testing? It seems like this is a common issue? Should I just write my own unittest using the management commands?