diff --git a/src/Elasticsearch.Net/Connection/HttpConnection-CoreFx.cs b/src/Elasticsearch.Net/Connection/HttpConnection-CoreFx.cs
index 4bc25c4e4f7..a3c4c783f86 100644
--- a/src/Elasticsearch.Net/Connection/HttpConnection-CoreFx.cs
+++ b/src/Elasticsearch.Net/Connection/HttpConnection-CoreFx.cs
@@ -75,7 +75,7 @@ public virtual TResponse Request<TResponse>(RequestData requestData)
 				statusCode = (int) responseMessage.StatusCode;
 
 				responseMessage.Headers.TryGetValues("Warning", out warnings);
-				mimeType = responseMessage.Content.Headers.ContentType.ToString();
+				mimeType = responseMessage.Content.Headers.ContentType?.MediaType;
 
 				if (responseMessage.Content != null)
 					responseStream = responseMessage.Content.ReadAsStreamAsync().GetAwaiter().GetResult();