If not, what are you doing there?
You should probably insist -- diplomatically -- on a contract specifying deferred salaries and equity. Say, something that does not screw the company in case it doesn't get any revenues.
The way I look at contracts now is you and the company are being held to certain standards. The company promises that they will pay you x shares or x dollars and you promise that you will work for the company for a certain number of years to be fully vested.
Although it's still an experiment in progress, I think it covers several bases well: we get a shot clock on the amount of work we all have to put in and by when, and as long as we do that, we'll all get varying pieces of a pie that doesn't even exist yet. Self-reinforcing.