A sash lock (10) is provided for a sash window assembly (12). The sash window assembly includes an upper sash window (14) and a lower sash window (16). Each of the sash windows (14, 16) are mounted within opposed guide rails (20) on a master frame (22) wherein at least one of the sash windows is slidable within the frame (20) relative to the other sash window. The sash window assembly (12) further includes a keeper (26) for mounting on a rail of one of the sash windows. The keeper (26) includes a keeper surface (26a). The sash lock (10) includes a locking assembly (28) for mounting on an adjacent rail of the other of the sash windows. The locking assembly (28) includes a housing (30) having an aperture (32), an actuator arm (34) having a shaft (38) disposed along a rotational axis and within the aperture (32) of the housing (30), and a cam (36) having a cam surface (36a) for engaging the keeper surface (26a) of the keeper (26). The cam (36) also includes an engagement member (40, 52) to engage the shaft (38) of the actuator arm (34). The housing (30) of the locking assembly (28) includes two alignment tabs (33) that are each adapted to engage one of two alignment surfaces (26d) of the keeper (26).