Specifying associated type via protocol inheritance with generic where clause in Swift

Question

Compiling following code:

protocol Foo {
    associatedtype Element
}

protocol IntFoo: Foo where Element == Int {
}

struct A: IntFoo {
}

let intFoo: IntFoo = A()

produces error message: Protocol 'IntFoo' can only be used as a generic constraint because it has Self or associated type requirements.

Didn't I just specify an associated type requirement or am I doing it wrong?