A sash lock for single- and double-hung window installations having upper and lower sashes having respective lower and upper check rails. The sash lock includes a latch for being pivotably mounted to the upper check rail of the lower sash, and a catch for being fixedly secured to the lower check rail of the upper sash. The latch includes a draw member, and the catch has a concave surface for being slidably engaged by the draw member. The concave surface is configured so that when the draw member is increasingly engaged with the catch the sash lock forces the upper and lower sashes into proper vertical alignment with one another regardless of whether upper check rail of the lower sash is initially above or below the lower check rail of the upper sash.