An occupant retention structure for a child's stroller utilizes an abbreviated upper horn extending downwardly from the underside of the tray and an abbreviated lower horn that extends upwardly from the seat pan beneath the lower horn without connection therebetween. Other protuberances formed by the tray and seat structures cooperates with the upper and lower horns to prevent the passage of a small probe used to determine if a child's torso or head could pass through an opening. The tray is mounted on a forwardly extending mounting pin for rotation thereon, while being rotatable about an axis of rotation perpendicular to the mounting pin to provide a swivel connection for the tray on one of the arm rests. A spring-loaded detent allows the tray to be released from the mounting pin for removal thereof from the stroller. The opposing end of the tray is latched to the other arm rest.