Floppy NS door mirror

Morning all, just wondered if there us a fix for a floppy door mirror on a non powered door mirror.
If I have to pull in close in the Devon lanes to let something pass and there is something larger than a piece of bracken in the hedgerow, it pushes the mirror in towards the car. Is there any way that the mirror pivot can be tightened up please?

Sounds like the locking mechanism has got damaged, possibly by a heavy impact earlier in it's life. You may be able to resurrect the mechanism, but you'll need to pull it apart to take a look. You can access it from below the pivot point, by removing the cover plate.

Thanks Nodge, will have a look!