Linguistic modal conventionalism says that modal truth depends on conventional rules governing the use of language. Historically, this theory has its roots in the positivist position that necessity is equivalent to analyticity. Its recent proponents have focused on defending it from Quinean objections to analyticity and Kripkean objections based on the existence of synthetic necessary truths. I argue that linguistic modal conventionalism must also deal with a dilemma that arises in its treatment of both de dicto and de re modal truths. On the one hand, if modal sentence truth is treated as conventional but modal properties and modal propositions are accepted as non-conventional, the theory’s commitments are too weak to be of interest. On the other hand, if modal properties and modal propositions are treated as conventional, the theory risks becoming committed to conventionalism about objects and non-modal truth.