A barrier device preventing access of pests such as mosquitoes, flies, and other small animals as well as debris between a panel pet door and a screen door by providing a seal between the panel pet door and the screen door. The barrier material may have ribs for the purpose of added stiffening or as a guide for adjusting the reach of the barrier. A stopping device may be used to ensure the screen door is closed to a location where good contact is made with the barrier device.