Change the order of the sub-tasks

It would be great to be able to rearrange the order of the sub-tasks. Maybe with a drag and shift click, just like it is possible with the main tasks.
As we add more sub-tasks to a main task, being able to change the order that they need to be completed would be so helpful. We always refine our process, so changing the tasks' order is a must-have feature. Thanks ;)