Canadian wiring question - PSE ADVISE!!!?

Just changed light fittings in an older house, 50 odd years old. Only a black wire plus white wire protruding. These attached to same in old light fitting. New fitting had a ground wire but nowhere to attach to. Bracket on new fitting had a green screw marked 'GND' so I attached to that. Pse advise if this is correct & safe. Seems to be working OK but concerned a potential danger lurking!!! Thank you!!