Run-flat support (1, 2) adapted to be mounted on a rim inside a tire, comprising a substantially cylindrical base (100) adapted to fit around the rim, a substantially cylindrical crown (101) and an annular body (102) linking the base and the crown. The body is composed of a plurality of generally radial partitions (103) distributed over the circumference of the support and of generally radial junctions (106) extending circumferentially and connected by their ends to two adjacent partitions. These junctions (106) are interrupted by very narrow axial incisions (104) extending radially over the entirety of the junction and opening axially on either side of the junction.