Sends wrong old_username to users

In case this is still supported…

If I as admin change usernames manually, in the notification email the wrong old_username is sent.

Instead of the users username, itsends the name of the current user:

function username_changer_template_tag_old_username( $old_username, $new_username ) {
	$current_user = wp_get_current_user();
	$username     = $current_user->user_login;

	return '<strong>' . $username . '</strong>';
}

Which would be me… ??