Why is the following template declaration ill-formed?

Why is the following declaration invalid?

template<template<typename> typename T>
struct S {};

I would assume this was valid since the following is valid:

template<template<typename> class T>
struct S {};

and what I can read from the standard in [gram.temp] it appears to be valid, but gcc gives me the following output:

prog.cpp:4:38: error: expected 'class' before 'T'
 template<template<typename> typename T>
                                  ^