I had the same problem with my bag becoming unzipped. I wanted Jamie to able to stick her little head out but she used to push on the zipper and it would unzip. My simple solution was to take a twist tie and tie one end to the ring on the zipper pull and another to the ring on the one of the handles at that end of the bag. It worked like a charm. The zipper will not go past a certain point and she can stick her little head out. She can't jump out either because her body won't fit through the opening. Now that she is getting used to the bag, she is fussing less, also. We both love our bag. Hope this solution works for you.