How should I list an "unofficial" major on my resume?

At my college, students are not allowed to major in more than one of the core (accounting, finance, marketing, management, operations management) business majors. So I officially majored in finance, but then took all of the accounting requirements as electives.

My question is this: is it appropriate to list accounting as a major on my resume even though it doesn't appear or my degree or transcript as a major? I could show the employer that I took all of the required classes if a question came up about it.

This won't be a big deal once I become a CPA and I will feel comfortable not having my resume say I was an accounting major at that point. But in the meantime, I was thinking that it might be nice for me to be able to show employers that I know a thing or two about accounting. I won't be able to actually become a CPA for at least 2 years.

Thanks for your opinions!