[bombcar]

There are heavy ones (cast iron doorstop will find some) and they work better in certain cases.

You can also use a doorstop to wedge a door slightly open so it won't close and auto-lock.

[mikewarot]

If the door has a deadbolt as well as a lock, you can use the deadbolt to ensure that the door doesn't auto lock by locking it with the door open.