A closure (10) of the flip-top type, and a closure combined with a bottle or other container The closure comprises a cap base (12) which can be releasably fastened to a package (74), the cap base including an opening. A closing flap (16) is movably attached to the cap base and is suitable, when it is in a closed position, for preventing egress of a liquid from the package through the cap base opening. The closing flap has a locking flap extending therefrom, and movably attached to the closing flap. A locking flap fastener (70) is provided for releasably securing the locking flap to the cap base or to the package to prevent inadvertent opening of the closure during transport and use by the consumer. The locking flap (38) may be tucked within the closing flap during normal use and used to lock the closing flap during transport. The locking flap may be disposed in a recess (20) in the cap base.