/testforblocks fails with enchanting tables

The bug

When using /testforblocks to determine if two blocks are identical, enchantment tables are always considered different, even if they are the same.

How to reproduce

1. /setblock ~1 ~ ~ enchanting_table
2. /setblock ~-1 ~ ~ enchanting_table
3. /testforblocks ~1 ~ ~ ~1 ~ ~ ~-1 ~ ~
→ "Source and destination are not identical"

Notes

Since this only occurs with enchanting tables after the player approaches them, this is probably caused by the rotation of the book. Why the server even knows about that, let alone serializes it, is anyone's guess.