How to fix Error 127 (flake8: no such file or directory)?

I'm trying to create a makefile for some code I wrote for an assignment. I need to be able to perform various style checks, type checks, etc. I'm using a makefile for this, and when I try executing a flake8 style check, I get an error:

flake8 .make: flake8: No such file or directorymake: *** [Makefile:58: check-style] Error 127

How can I get around this? I have a flake8 file in the same directory as the makefile, so I'm not sure why it's not recognizing it.