A shroud segment for a gas turbine engine, the shroud segment constructed from a composite material including reinforcing fibers embedded in a matrix, and having a cross-sectional shape defined by opposed forward and aft walls, and opposed inner and outer walls, the walls extending between opposed first and second end faces, wherein the inner wall defines an arcuate inner flowpath surface; and wherein a compound fillet is disposed at a junction between first and second ones of the walls, the compound fillet including first and second portions, the second portion having a concave curvature extending into the first one of the walls.