Stiff Leg DL/Good Morning Lower Back Tightness

Question regarding stiff legged deadlift and good mornings. I noticed beginning last week and this week that when I attempt to do either of these exercises I get a lower back tightness. When I mean tight I mean you could bounce a quarter clear to the moon off of my lower back. When I reach back I can feel my lower back (in the kidney area) is very, very tight. Does not hurt when I squat, but does tighten up when doing SDL or the good mornings.

Any suggestions?

Pretty common thing if you are new to good mornings and stiff leg deadlift. Just make sure you are arching (not rounding) your back as hard as possible and pushing your hips back so you keep the weight on your heels. I love good mornings though because out of all the exercises I do, they inflict the most soreness.