Common ground wiring for TXB0108 level shifter?

forgive my completely noob question, I'm well aware that it is, but I need to be sure before I power this thing up.

I need to talk serial between a Rasbperry Pi B+ and an UNO. 3.3v on one side, 5v on the other. I went with the adafruit level shifter which is utilizing the TXB0108 chip. http://www.adafruit.com/product/395

Enter the stupid question: The chip only has a single ground, so am I supposed to carry the ground common between the Raspberry Pi and the arduino?

This is how I have thus far planned to wire it if so, but please somebody yell out if I should stop from plugging it in.

I don't know what's wrong with that img link, but the url is http://imgur.com/LCHjV3r

Short answer is yes you should have a common ground.

ChilliTronix: Short answer is yes you should have a common ground.

Awesome, Thank you! Short answer was all I needed.