Slice at time t = 0.4 and constant y of the primitive quantities from the Balsara4 test performed in the MFM mode. The magnetic field divergence in units of its intensity is plotted in the bottom panel. Blue squares mark the solution computed with Powell terms only, while red triangles indicate the one computed with the complete divergence cleaning scheme. The high-resolution run is displayed with orange circles. Quantities v_z and B_z are not plotted but exhibit analogous behaviours to v_y and B_y. The correct solution, evaluated through the exact Riemann solver by Giacomazzo & Rezzolla (2006), is plotted with a dashed black line.