Slight Upper Back Rounding During Squats

I have been noticing that my upper back rounds slightly when I am close to failure in squats. Is it technique or a weak back that causes this? I squat high bar, and very far below parallel I am normally very upright while squatting.

I’ve noticed the same thing myself. If it’s truly upper back, then I’d try pulling the elbows together behind your back. If it’s midback, I’m not quite sure.

Most likely your. Upper back is becoming fatiqued as you get closer to failure I am assuming your squatting a decent amount of reps probably 5+. You can try a few things ie…
Obviously getting your upper back stronger should be goal one but in the mean time you can lower reps. Less reps mean less fatique on the musclea that stabalize and try to to hold the weight in place.