changing undergrad major after you've been accepted?

I was recently accepted to a couple of great schools for a phd and in my application I mentioned that I was a double major in both political science and philosophy (and was declared a double major at the time). However, now that my second semester started, I realized that I don't have the necessary requirements for a double major and I have to drop philosophy. Would that be an issue for the school I'm going to? They've already seen my courses except my last semester.