You can see through the ceiling made from stairs while riding a camel

You can see through the ceiling made from stairs while riding a camel
What I expected to happen was...:
Starting to see wooden plank texture

What actually happened was...:
I could see through the ceiling

Steps to Reproduce:
1. Place stairs 4 blocks above the ground facing normal way (bigger part of the block should be lower). Height between stair and ground should be 3 air blocks
2. Get camel and put saddle on it
3. Ride the camel under stairs and you can see through the ceiling