Confusing Template error

I've been playing with clang a while, and I stumbled upon "test/SemaTemplate/dependent-template-recover.cpp" (in the clang distribution) which is supposed to provide hints to recover from a template error.

The whole thing can be easily stripped down to a minimal example:

template<typename T, typename U, int N> struct X {
    void f(T* t)
    {
        // expected-error{{use 'template' keyword to treat 'f0' as a dependent template name}}
        t->f0<U>();
    }
};

The error message yielded by clang:

tpl.cpp:6:13: error: use 'template' keyword to treat 'f0' as a dependent template name
         t->f0<U>();
            ^
            template 
1 error generated.

... But I have a hard time understanding where exactly one is supposed to insert the template keyword to have the code to be syntactically correct?