Quaternion.LookRotation giving strange output

So...I'm trying to rotate my transform so it will align itself to the direction of motion.

In the past I've simply used

 projectile.transform.rotation = Quaternion.LookRotation(projectileRB.velocity);

and had the expected output. Now, I'm getting rotation around a different axis than I expect and it breaks the functionality of my projectile mechanics. Has anyone encountered this?