Path filtering inside pull requests

Is it possible to filter file changes inside the “on: pull_request” event? Something like this:

on:
  push:
    branches:
      - master
    paths:
      - 'thing/*'
  pull_request:
    branches:
      - master
    paths:
      - 'thing/*'

It doesn’t seem to work for me, the action runs even if the change is not in the thing directory 

This is just me being dumb. It’s because previous commits in the PR had diffs in the file glob that the action was still being triggered. Duhh…