The zircon-type GdVO4 is an interesting compound for magnetic refrigeration at low temperature, similarly to the previously studied monazite-type GdPO4. For the phosphate, neutron diffraction shows that long-range magnetic ordering at TN = 0.77 K is a delicate balance between dipolar andexchange interactions in a frustrated lattice. The magnetic structure, as obtained by minimizing the dipolar energy, is characterized by a negligible exchange energy difference with respect to the disordered state. For the vanadate, the much higher TN = 2.5 K makes us believe that magnetic frustration is not so determining and ordering should proceed differently. Therefore, GdVO4 is an interesting study case, not only in an application perspective but also from the fundamental point of view. We ask for 5 days in the D9 instrument to determine the magnetic structure at 1.8 K. Short wavelength is necessary to avoid the huge absorption of Gd for thermal neutrons but acceptable for lambda = 0.5 A.