Reverse lights aren't working after T5 swap

I swapped to a T5 and I just noticed today that the reverse lights aren't working. I remember only plugging two things into the T5, the speedo cable and the neutral safety plug. Is there a back up light harness I missed somewhere? Or is that round plug on the driver's side of the T5 the reverse light plug? Does it plug in any particular way?

I read the chilton's manual and it says that that connector on the side of the tranny is the back up light harness. I have it plugged in so I don't get why it's not working. Maybe it has to go the other way around?