A rotor for an electric machine is provided. Permanent magnets are disposed on the rotor such that the permanent magnets cannot carry out any tangential movement. The rotor may have four shoulders that extend away from a shell surface of the rotor in a radial direction. Primary permanent magnets that are disposed so as to be mutually contiguous and contiguous to the respective shoulders and accordingly cannot be displaced are in each case located between the shoulders. Secondary permanent magnets are disposed on the shoulders such that an annulus of magnets that is free of gaps and voids and is not movable in the tangential direction is formed.