The temperature dependence of the interlayer exchange coupling has been investigated in epitaxial tunnel junctions Fe1/MgO/Fe2/Co/V with thin MgO layers using X-band ferromagnetic resonance (FMR) in the range 2-300 K. Variations of FMR parameters allow concluding that the coupling strength increases with temperature. This is in agreement with predictions of the theories considering pure tunneling mechanisms and contradicts the model of a resonant assisted tunneling related to defects in the insulator. The temperature dependence of the FMR linewidth shows the line narrowing under the sample heating. This may be due to the additional mechanism associated with the coupling.