Union with elements seen as empty union

[ThisDevDane]

The following code produces the error test.odin(23:5) Invalid use of an empty union 'Element'

import "core:fmt.odin";

Symbol :: struct {
    name: string,
    value: Element,
}

Cons :: struct {
    car, cdr: Element,
}

Element :: union {
    ^Symbol,
    ^Cons,
}

main :: proc() {
    fmt.println("TEST");
}

while this doesnt

import "core:fmt.odin";

Symbol :: struct {
    name: string,
}

Cons :: struct {
    car, cdr: Element,
}

Element :: union {
    ^Symbol,
    ^Cons,
}

main :: proc() {
    fmt.println("TEST");
}