Diaper free for the night

Png Png passes urine in the toilet bowl, he wears diaper only when he wants to pass motion. I thought perhaps I could try him for diaper free for the night since he is already diaper free for afternoon nap. I asked him if it is fine not to wear diaper to sleep. He agreed. The next morning, the bed was not wet. He got through without accident for all the nights thus far without diaper. YIPEE!! I never expect his night training is so smooth.