Ask HN: How do you address unjustified compensation inequality?

Just for the sake of argument let's assume that there's no doubt about the fact the a coworker has no good reason to have a higher salary/more stock options than you. You both started around the same time and have the same title in the company. Let's even say that your contributions even had a higher impact on the company. You find out about this inequality in terms of compensation, what do you do? How do you address this?