A platform for a gas turbine engine has an outer surface and an inner surface. The inner surface is provided with a mount location for mounting the platform to a rotor. The platform extends from a leading edge to a trailing edge, and between a suction wall and a pressure wall. A circumferential direction is defined between the suction wall and the pressure wall. A tab extend circumferentially outward of one of the suction and pressure walls from the platform. The tab has a circumferentially outermost portion which will abut an inner surface of an adjacent platform when the platform is mounted. A fan section and a gas turbine engine are also disclosed.