On a separate note, I wanted to forewarn you that the automocker’s ClassUnderTest object is immutable once created; therefore, its dependencies are immutable as well. (Calling the PartialMockTheClassUnderTest() method also creates or replaces the ClassUnderTest object.) Since you are explicitly creating it in your Establish block in the base class (_rhinoAutoMocker.ClassUnderTest), you would never be able to inject your own dependencies. Instead, you would only get the dependencies RhinoMocks created for you. This caused a little havoc for me when my specs were not behaving as expected when I was trying to partial mock the class as a convention.