How to remove an old water stain?

[Goatblu]

From cotton trousers. I managed to get some trousers I'd been waiting for in the size I needed as an absolute bargain.

However, there's a slight mark on the waistband which looks like an old water mark.

Before I throw them into the washer, is there anything I can do to lift the stain before washing - or will washing be enough?

If it’s literally just water, immersing it water should remove it. In case there’s anything other than water involved, I suggest a cold wash first, which won’t set a stain. Then see what happens and you can try stain removal after that.

Thank you @hatboxes. I'll try a cold water wash first.