Sandstone and cobblestone slabs do not show the correct names

What I expected to happen was...:
the slabs to show "Sandstone Slab" and "Cobblestone Slab" in the creative menu

What actually happened was...:
The slabs show tile.stoneslab.cobblestone.name
and tile.stoneslab.sandstone.name

Steps to Reproduce:
1. Go to the creative menu and scroll over the 2 slabs