Slabs and walls are the same height

What I expected to happen was...:
I would move up half a block after walking on stone walls than moving onto a stone slab. 

What actually happened was...:
My character height stayed with the wall it didn't update to me standing on a stone slab. 

Steps to Reproduce:
1. Place walls
2. Place a slab
3. Walk on the slab and your character stays the same height as if you are standing on a wall.