Right side of turret sprite is facing mouse rather than the front of the turret

Basically the title explains it.

I've got a turret sprite that I want the front (barrel side) of to face my mouse.

Unfortunately what is actually occurring is the right side is facing the mouse instead.

Here is a GIF of whats occuring:

https://gyazo.com/b239d0303cdc071abf90f2d952f97a98

 void Update()
     {
 Vector3 mousePos = Input.mousePosition;
 mousePos.z = 5.23f;
 
 Vector3 objectPos = Camera.main.WorldToScreenPoint (transform.position);
 mousePos.x = mousePos.x - objectPos.x;
 mousePos.y = mousePos.y - objectPos.y;
 
 float angle = Mathf.Atan2(mousePos.y, mousePos.x) * Mathf.Rad2Deg;
 transform.rotation = Quaternion.Euler(new Vector3(0, 0, angle));
 
 }