Glock 19 digs into back when sitting

I recently got a Glock 19 to carry in an Aliengear cloaktuck 3 with an alien gear belt. I'm trying to carry it about 4:30. The only problem is that when I sit down, the bottom of the grip digs into my back. Does anyon have a suggestion to try and prevent this? I previously carried an XDs, so a gun this big is a different beast. via /r/CCW http://ift.tt/2hRQ3VT