A tunnel magnetoresistance effect is observed in magnetic tunnel junctions with an original zero magnetization ferromagnetic electrode composed of Sm1−xGdxAl2. A finite tunnel magnetoresistance is measured when the Sm1−xGdxAl2 electrode is in a magnetic compensated state proving that Sm1−xGdxAl2 with zero magnetization is able to give rise to a spin-polarized current. The temperature dependence of tunnel magnetoresistance reveals that this effect is related to the relative orientation of spin contributions to magnetic moment in both electrodes and that the tunnel polarization of the Sm1−xGdxAl2 electrode is negative.