A fluid container for a medical fluid dispensing device, comprises a rigid body (3) for delimiting with the inside part of its wall a volume of the medical fluid, and a membrane (5) that covers at least an opening of the rigid body thereby creating a fluid tight lid, the opening corresponding to a measurement area, and the membrane further covers a portion of an outside part of the rigid body's wall. The membrane comprises a flexible measurement part (11) corresponding to the opening of the rigid body, an attachment part (13) that is fixed to the rigid body, and a second part (12) that connects the flexible measurement part to the attachment part, and which comprises a rigid part (14), an upper part of which is connected to the flexible measurement part, and the rigid part further comprising a sealing surface (18), and a deformable part (15) which connects the rigid part to the attachment part. The fluid container further comprises a first gap (17) located between the rigid part and the rigid body, which is dimensioned to receive at least a part of the rigid part in a case when a force is applied onto the sealing surface and causes the deformable part to deform.