Port Forwarding to changing internal IP address

I have a security IP cam that I like to check remotely. Everything is set up fine. I have set up my router to forward to the port I have assigned to the cam, etc. Here is the problem. My ISP periodically changes the local IP assignment to the cam and then the forwarding fails because it is only set up to work with a single local IP address. Is there a way to forward to more than one local IP address in case the assignment changes? Or is there some other way to ensure uninterrupted remote access to the camera?