diff --git a/src/Http/Headers/ref/Microsoft.Net.Http.Headers.netcoreapp.cs b/src/Http/Headers/ref/Microsoft.Net.Http.Headers.netcoreapp.cs
index 41d44ad26d..74bfe68f38 100644
--- a/src/Http/Headers/ref/Microsoft.Net.Http.Headers.netcoreapp.cs
+++ b/src/Http/Headers/ref/Microsoft.Net.Http.Headers.netcoreapp.cs
@@ -200,6 +200,7 @@ namespace Microsoft.Net.Http.Headers
         public static readonly string WebSocketSubProtocols;
         public static readonly string WWWAuthenticate;
         public static readonly string XFrameOptions;
+        public static readonly string XRequestedWith;
     }
     public static partial class HeaderQuality
     {
diff --git a/src/Http/Headers/src/HeaderNames.cs b/src/Http/Headers/src/HeaderNames.cs
index 368cd8be46..5a30679fd8 100644
--- a/src/Http/Headers/src/HeaderNames.cs
+++ b/src/Http/Headers/src/HeaderNames.cs
@@ -88,5 +88,6 @@ namespace Microsoft.Net.Http.Headers
         public static readonly string WebSocketSubProtocols = "Sec-WebSocket-Protocol";
         public static readonly string WWWAuthenticate = "WWW-Authenticate";
         public static readonly string XFrameOptions = "X-Frame-Options";
+        public static readonly string XRequestedWith = "X-Requested-With";
     }
 }
diff --git a/src/Identity/test/InMemory.Test/FunctionalTest.cs b/src/Identity/test/InMemory.Test/FunctionalTest.cs
index b193bc16cd..a2609b4a43 100644
--- a/src/Identity/test/InMemory.Test/FunctionalTest.cs
+++ b/src/Identity/test/InMemory.Test/FunctionalTest.cs
@@ -18,6 +18,7 @@ using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Identity.Test;
 using Microsoft.AspNetCore.TestHost;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Net.Http.Headers;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Identity.InMemory
@@ -425,7 +426,7 @@ namespace Microsoft.AspNetCore.Identity.InMemory
             }
             if (ajaxRequest)
             {
-                request.Headers.Add("X-Requested-With", "XMLHttpRequest");
+                request.Headers.Add(HeaderNames.XRequestedWith, "XMLHttpRequest");
             }
             var transaction = new Transaction
             {
diff --git a/src/Security/Authentication/Cookies/src/CookieAuthenticationEvents.cs b/src/Security/Authentication/Cookies/src/CookieAuthenticationEvents.cs
index a6bb4e7d1c..a751c3eb53 100644
--- a/src/Security/Authentication/Cookies/src/CookieAuthenticationEvents.cs
+++ b/src/Security/Authentication/Cookies/src/CookieAuthenticationEvents.cs
@@ -9,7 +9,7 @@ using Microsoft.Net.Http.Headers;
 namespace Microsoft.AspNetCore.Authentication.Cookies
 {
     /// <summary>
-    /// This default implementation of the ICookieAuthenticationEvents may be used if the 
+    /// This default implementation of the ICookieAuthenticationEvents may be used if the
     /// application only needs to override a few of the interface methods. This may be used as a base class
     /// or may be instantiated directly.
     /// </summary>
@@ -103,9 +103,9 @@ namespace Microsoft.AspNetCore.Authentication.Cookies
 
         private static bool IsAjaxRequest(HttpRequest request)
         {
-            return string.Equals(request.Query["X-Requested-With"], "XMLHttpRequest", StringComparison.Ordinal) ||
-                string.Equals(request.Headers["X-Requested-With"], "XMLHttpRequest", StringComparison.Ordinal);
-        }		
+            return string.Equals(request.Query[HeaderNames.XRequestedWith], "XMLHttpRequest", StringComparison.Ordinal) ||
+                string.Equals(request.Headers[HeaderNames.XRequestedWith], "XMLHttpRequest", StringComparison.Ordinal);
+        }
 
         /// <summary>
         /// Implements the interface method by invoking the related delegate method.
diff --git a/src/SignalR/clients/csharp/Client/test/UnitTests/HttpConnectionTests.Transport.cs b/src/SignalR/clients/csharp/Client/test/UnitTests/HttpConnectionTests.Transport.cs
index 0244af0afd..a15f18faa1 100644
--- a/src/SignalR/clients/csharp/Client/test/UnitTests/HttpConnectionTests.Transport.cs
+++ b/src/SignalR/clients/csharp/Client/test/UnitTests/HttpConnectionTests.Transport.cs
@@ -15,6 +15,7 @@ using Microsoft.AspNetCore.Http.Connections;
 using Microsoft.AspNetCore.Http.Connections.Client;
 using Microsoft.AspNetCore.Http.Connections.Client.Internal;
 using Microsoft.AspNetCore.SignalR.Tests;
+using Microsoft.Net.Http.Headers;
 using Xunit;
 
 namespace Microsoft.AspNetCore.SignalR.Client.Tests
@@ -162,7 +163,7 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
 
                 testHttpHandler.OnRequest(async (request, next, token) =>
                 {
-                    var requestedWithHeader = request.Headers.GetValues("X-Requested-With");
+                    var requestedWithHeader = request.Headers.GetValues(HeaderNames.XRequestedWith);
                     var requestedWithValue = Assert.Single(requestedWithHeader);
                     Assert.Equal("XMLHttpRequest", requestedWithValue);
 
diff --git a/src/SignalR/server/SignalR/test/WebSocketsTransportTests.cs b/src/SignalR/server/SignalR/test/WebSocketsTransportTests.cs
index 70b985851f..2c059c3edc 100644
--- a/src/SignalR/server/SignalR/test/WebSocketsTransportTests.cs
+++ b/src/SignalR/server/SignalR/test/WebSocketsTransportTests.cs
@@ -13,6 +13,7 @@ using Microsoft.AspNetCore.Connections;
 using Microsoft.AspNetCore.Http.Connections.Client;
 using Microsoft.AspNetCore.Http.Connections.Client.Internal;
 using Microsoft.AspNetCore.Testing;
+using Microsoft.Net.Http.Headers;
 using Moq;
 using Xunit;
 
@@ -103,7 +104,7 @@ namespace Microsoft.AspNetCore.SignalR.Tests
                 await webSocketsTransport.StartAsync(new Uri(server.WebSocketsUrl + "/httpheader"),
                     TransferFormat.Binary).OrTimeout();
 
-                await webSocketsTransport.Output.WriteAsync(Encoding.UTF8.GetBytes("X-Requested-With"));
+                await webSocketsTransport.Output.WriteAsync(Encoding.UTF8.GetBytes(HeaderNames.XRequestedWith));
 
                 // The HTTP header endpoint closes the connection immediately after sending response which should stop the transport
                 await webSocketsTransport.Running.OrTimeout();