 In 1944, Johns became commandant of the Engineer School at Fort Belvoir. The wartime Engineer School was responsible for the training of officers. Some were engineers in civilian life who were trained as officers; other were officers transferred from other arms who were given training in engineering subjects. The Officer Candidate School (OCS) prepared enlisted men for commissioning as officers. There had been strong criticism of the content of training courses from SWPA, where it was the norm for machinery to be operated around the clock and for engineer officers to supervise all manner of construction tasks. The commanders there felt that the training courses taught by the Engineer School were concentrating too much on leadership in combat, and not enough on technical matters, such the operation and maintenance of construction equipment. Johns reformed the curriculum, but by this time it was too late for the changes to have much effect in the overseas theaters of operations. For his work at Fort Belvoir, Johns was awarded the Legion of Merit.
