How to disable endermen from picking up blocks?

I am writing a plugin, and, so far, I am able to disable endermen from breaking and placing blocks, but I cannot disable them picking the blocks up.

Here is my code:

    public void onBlockBreak(final ChangeBlockEvent event) {
        if(event.getCause().root() instanceof Enderman) {
  ":::: prevented an enderthief!");

if you are preventing them breaking blocks, then there is nothing to pick up, so clarify what you mean??

Tip: You can use event filters, like this:

public void onBlockBreak(ChangeBlockEvent event, @Root Enderman enderman) {

@nap This is a known bug, you can participate on the issue here: knowing more people are interested in a fix helps triage.