Jedi Outcast used to be a 4:3 game but I can't get the game to run in 4:3 fullscreen. No matter which resolution I chose the game will automatically stretch to 16:9 fullscreen. Is there a method to fix this?

EDIT: Thanks to Genoan from the GOG support team for giving me the solution. All I had to do was changing the scaling from display to GPU in my Nvidia system control . Now the game is running in correct 4:3 resolution. Case closed. :)