diff --git a/src/Elastic.Clients.Elasticsearch/_Shared/Core/Request/RequestDescriptor.cs b/src/Elastic.Clients.Elasticsearch/_Shared/Core/Request/RequestDescriptor.cs
index 05723aa785..157552162a 100644
--- a/src/Elastic.Clients.Elasticsearch/_Shared/Core/Request/RequestDescriptor.cs
+++ b/src/Elastic.Clients.Elasticsearch/_Shared/Core/Request/RequestDescriptor.cs
@@ -59,8 +59,9 @@ protected TDescriptor Qs(string name, IStringable value)
 	/// </summary>
 	public TDescriptor RequestConfiguration(Func<RequestConfigurationDescriptor, IRequestConfiguration> configurationSelector)
 	{
-		var rc = RequestConfig;
-		RequestConfig = configurationSelector?.Invoke(new RequestConfigurationDescriptor(rc)) ?? rc;
+		RequestConfig = configurationSelector?.Invoke(RequestConfig is null
+			? new RequestConfigurationDescriptor()
+			: new RequestConfigurationDescriptor(RequestConfig)) ?? RequestConfig;
 		return _descriptor;
 	}