Loose rearview mirror?

[HoosierJeeper]

Ever since I got my 09 WK the rearview mirror shakes when the pavement is anything less than new. There's some play in the joint on it...I know mirrors do shake a bit, but this shakes more than any other vehicle I've had. Just wondering if there's a way to tighten it up.

Here's the mirror.
https://theultimatejeep.com/images/imported/2013/10/photo12-1.jpg (http://s670.photobucket.com/user/wjkj/media/photo-12.jpg.html)

Thanks!