A window assembly may include a pane movable between open and closed positions, a cam having a cam surface, and a cam follower coupled to the movable pane for movement relative to the cam surface and engageable with the cam surface when the movable pane is near or in the closed position. The cam surface may be inclined toward a seal to direct the movable pane into the seal when the movable pane moves into the closed position. The cam surface may include a linear portion that extends along at least a majority of the path of travel of the movable pane. The cam follower may remain engaged with the cam surface throughout a desired portion of the path of travel of the movable pane.