A face sealing annular valve (1) for a fluid-working machine has an annular valve member (10, 50, 60, 70, 80, 90, 100, 110) having a relaxed configuration in which a first seat-engaging surface (14, 101) of the annular valve member can sealedly engage with a first sealing surface of an annular valve seat (8), but a second seat-engaging surface (15, 101) cannot sealedly engage with a second sealing surface (9), and is elastically deformable to a deformed configuration in which the second seat-engaging surface can sealedly engage with a second sealing surface, while the first seat-engaging surface remains sealedly engaged with the first sealing surface. The annular valve member can be made with relatively high tolerances and is only loosely retained by a guide in the relaxed configuration.