Girls, can you tell me, our baby is about to turn 5 months old. He has…

Girls, can you tell me, our baby is about to turn 5 months old. He has started to sit up on his own, but not through the side, rather by leaning forward. Is this normal? I saw somewhere that such attempts should be discouraged. But we constantly put him on his belly, and he doesn't want to lie on it anymore, he keeps wanting to sit up like this.