"Efficiency" enchantment does not work for shovels

I was gonna remove a dirt plateau with my diamond shovel enchanted with the "efficiency V" enchantment.

What I expected to happen was...:
As usual insta-mine the dirt and grass with ease.

What actually happened was...:
The shovel was mining wasn't insta-mining. It was mining very slowly, so i compared it to an unenchanted diamond-shovel which resulted in the very same digging speed, leading me to the thought that the efficiency enchantment does not apply to shovels.

Steps to Reproduce:
1. Enchant a shovel with the efficiency (V) enchantment
2. Dig sand/dirt/grass/gravel
3. Compare to other versions to see the lack of speed or compare to unenchanted shovels to see the lack of difference