Once the button is secure, it is time to finish the repair on the inside, with a knot.

Carefully pass the needle through the loops of thread on the backside of the repair, taking care not to pass it through the fabric itself.

Careful: Do not pull tight! Leave a loop large enough to pass the needle through.

Pass the needle through the loop, and now pull tight to create the knot. Repeat this process once more to add a second knot, for extra security.