How do I squash a widget in a grid layout down to the bottom to its minimum size?

[enjoysmath]

I have a widget I made in Qt Designer and a QGraphicsView. I'd like:

[QGraphicsView]
[ " ]
[ " ]
[ " ]
[ " ]
[ " ]
[MyCustomWidget]

Instead, the layout is coming out like this:

[QGraphicsView]
[MyCustomWidget]

ie. 50 /50 split of vertical space. I've played around with the row/column span versions of gridLayout.addWidget(), and they didn't make any difference.

Thanks.