Tall cleans (or snatches if you're experiencing the same thing in the snatch) or high hang lifts (with no hip angle break if possible) will help correct that arm bend issue. You can also work from blocks. You can also do pulls + lift (e.g. 2 pulls + snatch/clean) and making sure that you focus on the technique during those 2 pulls.
Hope this helps!
Javier A. Sanjuan
Olympus Barbell Club
Dear God, please help me lift heavy and be awesome. Thanks. Amen.