Approval ignores new commits to PR

Steps to reproduce:

1. Fellow developer creates new branch and commits changes, makes PR.
2. You open the PR in browser and start the review. While you review, fellow developer pushes some new commit(s) to branch/PR.
3. The reviewer (you) has no way to see that the PR has changed and gives approval based ONLY on the initial commit.

BitBucket is happy to accept that and allows the fellow developer to merge, while actually NOBODY reviewed the subsequent commit.

Expected behavior:

BitBucket should reject the approval and notify the reviewer that he/she is approving an outdated version of the PR.

This behavior would be in line with another automatic behavior that BitBucket already has: automatically removing approval if new commits are added after PR is approved.