The present invention relates to a yoke ring for use in a deflection unit in a cathode ray tube (CRT). The yoke ring having a neck and a flared side, and being defined by an inner and an outer contour. According to the invention, the inner contour is periodically deformed in the radial direction, the contour having at least two local minima and maxima. This deformation influences the magnetic field generated by the coils in the CRT, leading to improved front-of-screen performance. In particular, astigmatism, coma and raster errors are reduced.