A trace of beryllium can lead to dramatic grain coarsening in Mg–Al alloys at normal cooling rates. It is, however, unclear whether this effect applies to aluminium-free magnesium alloys or not. This work shows that a trace of beryllium also causes considerable grain coarsening in Mg–Zn, Mg–Ca, Mg–Ce and Mg–Nd alloys and hinders grain refinement of magnesium alloys by zirconium as well.