Provided is a bearing for a wind turbine, including a first and a second ring arranged radially to each other with one ring rotating relative to the other ring around an axis of rotation. The first ring has a cylindrical ring section and a collar extending radially from the ring section. The collar has an axial support area supporting axial bearing elements, wherein several pretension elements creating compressive stress are fixed to the first ring in the section where the collar extends from the ring section.