The interest in the noncollinear antiferromagnet Mn3Ge was stirred by the recent observation of an anomalous Hall effect (AHE) driven by nonvanishing Berry curvature, which typically vanishes for conventional (collinear) antiferromagnets. Our most recent anomalous-Hall- effect and magnetization measurements suggest a very strong sensitivity of the magnetic transitions and presumably of the magnetic structure and AHE to hydrostatic pressure. Even very modest pressures of the order of a few kbar led to a notable reduction of the antiferromagnetic transition temperature and to the stabilization of a new low-temperature magnetic phase. We propose to study the magnetic structure of this pressure-induced phase transition by neutron powder diffraction at the D2B instrument with the conventional clamp pressure cell and at D20 instrument with Paris-Edinburgh cell available at ILL.