Switching to the crib

My son is 13 months old. We are expecting baby #3 in January so we wanted to start putting him in his crib. He’s always slept in a porter crib in our room. He’s comfortable in there and calls us in the morning to wake us up. Well tonight was the first night I tried to put him in his crib and he hated it. He did not want to be in there. he was crying and seemed scared 🙁. I was upset for him so I brought him back into my room until I can figure out what else to do. Any advice on switching him over??