Items on top of chests don't get picked up by hoppers

If you drop an item on top of a chest and a hopper is underneath the chest, the item isn't picked up

What I expected to happen was...:
The item should get picked up, because a chest isn't higher than a block of farmland, and if you replace the chest with farmland the item gets picked up

What actually happened was...:
The item didn't go into the hopper

Steps to Reproduce:
1. Put a chest on top of a hopper and drop an item on top of it