A receptacle connector with a metal housing encircling an insulative housing with a slot to receive a paddle card of a plug connector. The metal housing may have a tab engaging a wall of the insulative housing bounding the slot. The tab may be positioned such that, if a plug is improperly inserted into the receptacle, it presses against the tab. The tab may be configured to distribute force generated during an attempt to mate a misaligned plug away from thin wall portions of the insulative housing at an end of the slot. The tab may extend over a surface of the insulative housing beyond that thin wall portion and may be recessed into the housing.