How do I set Turret rotation axis?

I have defined an off-center origin for my turret, but the Turret keeps rotating around the center of the sprite image, not the defined origin.

My turret sprite basically looks like: O---

I want it to rotate around the center of the turret base, not the middle of the barrel.

How can I do that?

I figured it out. It worked once I made the turret hierarchically a child to the hull.