A locking assembly for a casement window including a frame having an elongated surface, comprising a tie bar guide adapted to be mounted on the window frame surface, the tie bar guide having first and second receiving grooves for slideably receiving segments of a tie bar in a tongue and groove manner, and a tie bar adapted to slide axially in a direction parallel to the window frame surface and having a partially curved profile and a cross-section comprising a flat central portion with a first segment comprising a first tongue and a second segment comprising a second tongue, the first and second segments on opposite sides relative to the central portion. The tie bar is slideably received in the tie bar guide such that the tie bar first tongue is received in the tie bar guide first receiving groove and the tie bar second tongue is received in the tie bar guide second receiving groove, to permit the position of the tie bar to be adjusted with respect to the tie bar guide in the longitudinal direction while preventing movement of the tie bar in a direction perpendicular to the longitudinal direction. One of the tie bar and tie bar guide has an opening in an exterior surface thereof and the other has a projection extending in a direction of the opening, wherein when the tie bar is slideably received within the tie bar guide, the projection and opening act as a detent to maintain the tie bar guide in a desired position.