Recaptcha validator and medium trust

I was wondering how do you made Recaptcha validator works on medium trust.
I have a project with Recaptcha and get the security exception "That assembly does not allow partially trusted callers", but nopCommerce does not have the attribute that enable partially trusted callers in the assembly info.
What can i do?

Nothing. It works fine out of the box (downloaded on Recaptcha official site)