Breast interface (70) for a breast pump (1), including: a liner support frame (200) defining an interior liner support frame space (202) configured to receive at least part of a liner (100), said liner support frame including: a front ring (204) a split rear ring (206) including at least two complementary circumferential rear ring portions (206a, 206b) that are rearrangeable relative to each other to facilitate passage of a flanged rear end of a liner (100) and a liner (100) including: a rear section (170) including a tubular wall part that is configured to be fittingly enclosed by the rear ring (206) and that is provided with a first annular flange (172) with an outer diameter that is greater than an inner diameter of the rear ring (206) of the liner support frame (200), and that, in an assembled condition of the breast interface, abuts the rear ring (206) on end.