diff --git a/src/Proxy/ProxyExtensions.cs b/src/Proxy/ProxyExtensions.cs
index 3628eefc6..5ca6b4f4a 100644
--- a/src/Proxy/ProxyExtensions.cs
+++ b/src/Proxy/ProxyExtensions.cs
@@ -7,6 +7,7 @@
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Primitives;
+using Microsoft.Net.Http.Headers;
 
 namespace Proxy
 {
@@ -118,7 +119,7 @@ public static async Task CopyProxyHttpResponse(this HttpContext context, HttpRes
             CopyHeaders(responseHeaders, replyMessage.Content.Headers);
 
             // SendAsync removes chunking from the response. This removes the header so it doesn't expect a chunked response.
-            responseHeaders.Remove("transfer-encoding");
+            responseHeaders.Remove(HeaderNames.TransferEncoding);
 
             using (var responseStream = await replyMessage.Content.ReadAsStreamAsync())
             {