A child-resistant package includes a plastic container having a blow-molded neck finish with an end, at least one external thread, an arcuate part-circumferential ledge adjacent to the neck finish and a plurality of angularly spaced ratchet teeth on the ledge. A closure has at least one skirt, at least one internal thread on the skirt, at least one flexible resilient ratchet finger extending radially inwardly from the skirt at an angle to the skirt, and a seal element within the skirt for sealing engagement with the end of the container neck finish. Threading of the closure onto the container neck finish brings the ratchet finger into engagement with the ratchet teeth. The array of ratchet teeth and the seal element are such as to accommodate tolerance variations in the blow-molded neck finish while maintaining a seal and child-resistance capability at the neck finish. In an exemplary embodiment of the disclosure, there are a pair of angularly spaced ratchet fingers on the skirt, with the array of ratchet teeth, the seal element and the angular spacing between the ratchet fingers accommodating tolerance variations in the blow-molded neck finish. The closure preferably is a dual-wall closure having an internal skirt with the internal thread and an external skirt with the ratchet fingers.