A plug connector for media-bearing lines has a plug body for connecting to an opening. At least one rib is provided on the plug body, the rib being retained in the opening in the assembly position of the plug body by a retaining clip adjustable on the plug body. An assembly force acts on the retaining clip, the clip being supported on at least one rib of the plug body, thereby displacing the plug body into the opening, and locking therein in an undercut.