.NET NEST https error: The handshake failed due to an unexpected packet format

NEST 5.0-beta1

If I use https:// instead of http:// I get this error while indexing a doc.

var uri = new Uri("https://192.168.11.223:9200");
var settings = new ConnectionSettings(uri);
settings.BasicAuthentication("elastic", "xxx");
var elk = new ElasticClient(settings);

Invalid NEST response built from a unsuccessful low level call on PUT: /backups-2016.10.13/jobhistory/5fe2a8ec-ecc8-4592-8221-77af67c02fbb_7804

Audit trail of this API call:

OriginalException: System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a send. ---> System.IO.IOException: The handshake failed due to an unexpected packet format.

at System.Net.Security.SslState.StartReadFrame(Byte buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReceiveBlob(Byte buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartSendBlob(Byte incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)
at System.Net.TlsStream.CallProcessAuthentication(Object state)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Net.TlsStream.ProcessAuthentication(LazyAsyncResult result)
at System.Net.TlsStream.Write(Byte buffer, Int32 offset, Int32 size)
at System.Net.PooledStream.Write(Byte buffer, Int32 offset, Int32 size)
at System.Net.ConnectStream.WriteHeaders(Boolean async)
--- End of inner exception stack trace ---
at System.Net.HttpWebRequest.GetResponse()
at Elasticsearch.Net.HttpConnection.Request[TReturn](RequestData requestData) in C:\code\elasticsearch-net\src\Elasticsearch.Net\Connection\HttpConnection.cs:line 142

Request:

<Request stream not captured or already read to completion by serializer. Set DisableDirectStreaming() on ConnectionSettings to force it to be set on the response.>

Response:

<Response stream not captured or already read to completion by serializer. Set DisableDirectStreaming() on ConnectionSettings to force it to be set on the response.>