New kitten with a almost 2 year old dog?

I have a dog who is 1 and a half. And we new got a kitten, not sure of age it's something months. My dog has never been around a cat and I'm scared he will eat it. Well I been trying to get them to meet each other but the kitten keeps hissing and running away. I don't know what to do I don't want to get ride of any of them but they both have to sleep in my room. Any suggestions? Oh and the dog is a mastiff boxer mix