How to prevent New Window from offsetting location from previous windows?

I'm anal retentive. I like a tidy screen. I place all Firefox windows at top left corner of the screen. Each successive New Window arrives offset a small distance to the right, so that it does not cover the previous window. That's terrific, except... I do not want that behavior. I am constantly repositioning the New Window so that it too starts at the top left corner of the screen. It would be delightful if there were a Preferences option to allow New Windows to NOT be automatically offset to the right of the previous Firefox window.