A locking device having an upper portion, a lower portion, and a locking arm prevents a closed door from being opened. The locking arm is pivotably mounted to the lower portion of the locking device and positioned in cavities of the upper portion and the lower portion. A pivot bolt is operatively attached to the lower portion and an end of the locking arm. A locking bolt extends transverse and through the locking arm and through the lower portion for securing the locking arm. The locking bolt has a key or detent, which is received by a corresponding groove in the lower portion. The locking arm extends vertically from the lower portion upwardly above the lower edge of the door, thereby preventing the door from being opened outwardly when in a closed position. The upper portion and the lower portion are preferably bulbous shaped.