A connection device for interconnecting two components of plastics material is provided. The components include a first wall and a second wall, which have respective edges arranged against one another, when the two components are assembled. The device includes at least one clip on the first wall and extending beyond the edge thereof, at least one first tooth and at least one second tooth on the second wall and designed to be snap engaged by the clip when the two components are in the pre-assembled state and in the assembled state, respectively. The first tooth is closer than the second tooth to the edge of the second wall such that, when pre-assembled, the two components are connected by the edges of the first wall and the second wall, the edges being spaced apart from one another. The first tooth has an inclined locking face for facilitating decoupling of the two components.