With right sides together, match the side seam of the lining to the side seam of the waistband and secure with straight pins.

Stitch the lining to the inner waistband.

Turn the skirt right side out.

Top stitch along the bottom edge of the outer waistband to secure it to the inner waistband.

Make sure the seam allowance between the lining and the inner waistband is on the waistband side of the seam so the top stitching will secure it.