What if you don’t end up wanting a job in either of your majors? Would you tack on a third? A fourth? 
You can’t plan for everything. You can’t PREPARE yourself for a job in any given field. If you get to the end and decide you don’t want a job in field x, you might not have chosen your major well enough…but that’s why you usually have four years in college, not one or two. The first bit, a lot of people are changing their minds and their majors.