The nature of change was as resolved at the company's general meeting at the end of November.
Along with the options, Fotios holds four million shares.
Fotios brings extensive geological and management experience to Oklo, and is currently on the board of Eastern Goldfields, Horseshoe Metals, Pegasus Metals, and Redbank Copper.
He is also founder and executive chairman of unlisted investment company, Investment Limited.
Oklo has gold interests in a highly prospective area of West Africa.