Talking in his sleep

Do y’all know anyone that talks in their sleep?
My 3 year old has started talking in his sleep almost every night
One night he is talking to daddy about chasing rainbows 
Last night it was finding the right ball to play baseball with...
EVERY NIGHT he starts be calling for “MOMMY”
and every night it wakes me up and he will call for me till I go in and say what…but EVERY NIGHT when I get in there he is still fast asleep!

I don’t know if there is a way to STOP his sleep talking but if you know of any SHARE!!!
My 23 month old has just started sleeping though the night and I was getting excited about getting a full night sleep..but now I hear “MOMMY” at least once a night!