Mono: Compiling a WSDL

This post belongs to the I had a hard time finding this information so I put it somewhere I can easily find it again category.
I tried to compile a WSDL with mcs like this:

wsdl Service.wsdl
mcs /target:library Service.cs

and always got this error message:

Service.cs(22) error CS0234: The type or namespace name `Services' could not be found in namespace `System.Web'

I found this command after a long search on the Internet:

mcs /target:library Service.cs -r:System.Web.Services

Now everything seems to compile O.K. Let's see if the resulting .dll works.
I'll keep you posted.