distracted nursing..

so my baby is 4 months old and has figured out there's a whole world around him. yay! unfortunately, his favorite time to explore and look around is when he's nursing. so, we used to be able to nurse straight to sleep, and now it's gotten to where once he realizes that he's getting sleepy, he will look at everything he can to avoid nursing anymore. how do I keep baby focused on nursing?? he does it every time he nurses, not just bedtime nursing. it's just worse at bedtime. picture for cuteness 😊