A closure and container constitute a child-resistant package. The container has a finish with an open mouth, at least one external thread adjacent to the open mouth, and at least one external radial projection on a side of the at least one external thread that is spaced from the open mouth. The closure has a base wall, a skirt with at least one internal thread adjacent to the base wall for engagement with the at least one external thread to thread the closure onto the finish, at least one internal locking lug spaced from the base wall, and an annular wall extending from the base wall at a position spaced radially inwardly from the skirt for resilient internal engagement with the open mouth of the container. The at least one internal locking lug is engageable with the at least one external radial projection when the closure is fully threaded onto the finish of the container and resiliency of the annular wall holds the at least one internal locking lug in axial engagement with the at least one external radial projection.