I used the grind stone on an enchanted book with efficiency 1

What I expected to happen was...:
It would revert the item to a normal book

What actually happened was...:
The enchantment was taken off the book but not the "enchanted book" name of it

Steps to Reproduce:
1. enchant a book with any enchantment or efficiency 1 preferably in a enchantment table
2. put the book in a grindstone.
3. repeat if does not work the first time