Officials in Hoffman Estates, Ill., told the Arlington Heights (Ill.) Daily Herald the boy was stuck in the safe for nearly 20 minutes while firefighters sought a way to open the locked box.
The boy apparently was locked inside the safe at Cabela's recreation goods store after his brother forced him into it and spun the locking mechanism once the door was closed.
Fire Lt. Jay Martino was eventually able to free the boy after using another safe's keypad to open the door of the safe containing the child.
The identity of the boys, along with the age of the child's brother, was not reported.
The Daily Herald said the child was able to breathe inside of the safe, which was estimated to be 5 feet tall, 3 feet wide and 18 inches deep.