[1.10/1.11] Hopper support for multi-block inventories (like double chests)

I have implemented a chest-like tileentity that can be one or two blocks large, but I can't figure out how to allow hoppers and other types of automation access the entire inventory. I have a separate te for each block, and a separate container for each one, but when they are connected, opening one creates a separate container with all the items from both blocks. Hoppers,  however, only access the inventory of one block at a time.