Efficiency enchantment on shovels only works in Survival mode

When enchanting a shovel with Efficiency, the enchantment only works in Survival mode (that is, the shovel will dig at normal block-breaking speed in Creative, but will dig at its intended speed in Survival).

What I expected to happen was...:
The shovel would dig faster when I enchanted it in Creative mode.

What actually happened was...:
The enchantment added no visible effect, but upon switching to Survival mode, it worked.

Steps to Reproduce:
1. Enchant a shovel with Efficiency, through an enchanted book or /enchant
2. If not already in Creative mode, switch to it and dig with the shovel
3. Switch to Survival and dig with the shovel again