Seal (10) for an inter-blade platform intended to extend circumferentially about an axis and to be mounted between two axial ends of the inter-blade platform, including a first part (10a) in contact with a first blade adjacent to a first circumferential end of the platform, and a second part (10b) in contact with a second blade adjacent to a second circumferential end of the platform, the first part (10a) and the second part (10b) of the seal (10) being fixed to each other such that a displacement in the circumferential direction of one of the two parts (10a, 10b) of the seal (10) causes a displacement of the other part (10a, 10b) of the seal (10) in the same direction, when the two parts (10a, 10b) of the seal (10) are fixed to each other.