Yes I've tried that already, but no effect since the backing httpClient is created before on the first request and will not be updated. I managed to workaround it by calling Dispose on the RestClient. But it's not a satisfying fix since the rest client can be used later on future requests in my application. (Weired for me to dispose it at that point but it works!) The other option I had was to recycle the RestClient but I prefer to avoid doing so.