The power will be out to some residents of North Simcoe overnight tonight.
Hydro one is doing upgrades at its Waubaushene transmission station and will turn off the power for about four hours early Sunday morning between 4 a-m and 8 a-m.
The outage will affect more than 8,000 Hydro One customers in Tiny Township and the surrounding area including Beausoleil First Nation.
Approximately 5,400 Alectra Utilities customers in Penetanguishene will also be affected along, with more than 7,000 Newmarket-Tay Power customers in Midland.
Hydro one says the outage is needed to ensure the future reliability of the system.