Just put a blank sheet of paper in your passport next to your photo and the border guards on both sides would stamp the blank sheet without a word being said. Problem solved.
When I visited Cuba some time ago the border guys used to do exactly that (I don't have a US passport) so that you wouldn't get any hassle if you subsequently visited the States. I suspect if they hadn't it might have affected the number of people who were willing to visit and spend their tourist dollars.