OBS and geek window?

I have been having trouble capturing the geek window with OBS, and i have seen other streamers using obs with it. How can i fix/get it to show up on stream?

Thanks

It kinda works out of the box for me. Downloaded OBS 0.625 on OS X and Windows 7, added a Monitor Capture and clicked ‘Start Recording’ - it records the geek window.

See: https://www.youtube.com/watch?v=VC4e8AqD2iY&feature=youtu.be