When using @skip decorator, `reason` argument is required. But one could easily overlook that and use it like so: class SomeTest(TestCase): @skip def test_method(self): # ... The test actually passes when running with unittest, because it's equivalent to class SomeTest(TestCase): def test_method(self): # ... test_method = skip(test_method) This gives the illusion that @skip decorator worked as expected. I propose we should check the passed in `reason`, and raise error if it looks like a function/method, therefore prevent this erroneous usage. In practice, this behavior has misled people using the decorator in the unintended way. For example: In this chapter of Test-Driven Development with Python (http://www.obeythetestinggoat.com/book/chapter_organising_test_files.html), the author used @skip decorator without `reason` argument.