No, you don't have any options if the landlord will not let you have the addendum you want--and note: I do landlord-tenant law for a living and have *never* seen a landlord who is willing to only hold a tenant liable for his/her share of the rent. Consider it from the landlord's point of view: if your roommates fail to pay but you pay your share, under your proposal, the landlord would be unable to evict you and re-let the house in its entirety. Rather, he'd have to let you stay and essentially have the whole house to yourself even if you are just paying a fraction of the rent. That is unreasonable, and no landlord will do it. This is a risk of sharing a house with roommates--being liable for their default.