Overshoe sizing issue

I have just bought some Campag overshoes online and trying them on at home I find that the ankles are loose. Having never owned overshoes before am I right in assuming this shouldn't be the case? I assumed they would "seal" at the ankle.
I bought the XL as recommended by Campag's size guide as I have size 11 feet but I do have quite skinny ankles. Would the large have a significantly narrower ankle? Any advice appreciated, cheers.

I'm very skinny and my non-Campag overshoes are baggy on the ankle. It hasn't bothered me much.

Do we mean neoprene ones here - or the waterproof type ones?

If the former, then they shouldn't be baggy, if the latter, they always are IME, and my Alturas have a compression strap at the top of the arch to deal with it.

That said, with neoprene, if you get ones too snug for your shoe size, you are going to have other problems far worse than a baggy ankle.

Dan, how skinny are your aankles [ooooh hello cheeky]

nice little bodge is to get an old inner tube from something like a scooter/ moped ad just cut yourself some 'ankle cuffs' to create a seal between your delicate edwardian ankles and t'overshoes

Ah, an old pro's trick eh Wayne? Nice one.

Are they 'track'-overshoes?
Only 'road'-overshoes come with sealed ankles.

They be these:

http://www.chainreactioncycles.com/Models.aspx?ModelID=56389

I think using a piece of old inside tude is an excellent idea must try it out sometime.

They be these:

http://www.chainreactioncycles.com/Models.aspx?ModelID=56389

Those are definitely 'road' -ones, cause the 'track'-ones read "Campagnolo Pista" and have chrome-color toe-caps and a NJS-stamp next to the washing instructions.