Johan married Lily Van Nieuwenhuizen, daughter of Willem Karel Van Nieuwenhuizen and Jeannette Antoinette Westerkamp, in Jakarta, Indonesia. (Lily Van Nieuwenhuizen was born on 27 Feb 1917 in Buitenzorg (Bogor), Jawa Barat, Indonesia, died on 18 Dec 2002 in Netherlands and was buried on 23 Dec 2002 in Netherlands.)