"Drowning?" into blocks while walking down stairs

What I expected to happen was...:
I could walk smoothly (Well, of course ;-

What actually happened was...:
I go down the blocks infront of the stairs (going down) aka Drowning in the stairs lel

Steps to Reproduce:
1. Erm, just place stairs going up by 3, go down, you'll see it (there MUST be a block after the last stair, below it)
2. Your mom