How do I make this properly async?

asynchow

type ContentLengthHandler() =
    inherit DelegatingHandler ()    
    override __.SendAsync (request, token) =
        let resp = base.SendAsync(request, token).Result //GAH
        match resp.Content with
        | :? ObjectContent as oc ->
            let s = oc.ReadAsStreamAsync().Result //GAH
            resp.Content <- new StreamContent(s)
            resp.Content.Headers.ContentLength <- Nullable (int64 s.Length)
            Task.FromResult resp
        | _ -> 
            Task.FromResult resp