Spurious raw types warning when using unbound method references

The following code gives an undeserved warning:

interface Foo<X> {
    void m(List<X> lx, X x);
}

class Test {
    Foo<String> fs1 = List::add; //warning: List is a raw type
}

The warning is undeserved, as List type-parameters are being inferred from the context.