diff --git a/src/Servers/Kestrel/Core/src/Internal/Http/HttpHeaders.cs b/src/Servers/Kestrel/Core/src/Internal/Http/HttpHeaders.cs
index 3df0869931..272034f51a 100644
--- a/src/Servers/Kestrel/Core/src/Internal/Http/HttpHeaders.cs
+++ b/src/Servers/Kestrel/Core/src/Internal/Http/HttpHeaders.cs
@@ -111,6 +111,8 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             _isReadOnly = true;
         }
 
+        // Inline to allow ClearFast to devirtualize in caller
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void Reset()
         {
             _isReadOnly = false;
diff --git a/src/Servers/Kestrel/Core/src/Internal/Http/HttpRequestHeaders.cs b/src/Servers/Kestrel/Core/src/Internal/Http/HttpRequestHeaders.cs
index cd42a19a1f..414a8a04ac 100644
--- a/src/Servers/Kestrel/Core/src/Internal/Http/HttpRequestHeaders.cs
+++ b/src/Servers/Kestrel/Core/src/Internal/Http/HttpRequestHeaders.cs
@@ -11,7 +11,7 @@ using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 {
-    public partial class HttpRequestHeaders : HttpHeaders
+    public sealed partial class HttpRequestHeaders : HttpHeaders
     {
         private static long ParseContentLength(string value)
         {
diff --git a/src/Servers/Kestrel/Core/src/Internal/Http/HttpResponseHeaders.cs b/src/Servers/Kestrel/Core/src/Internal/Http/HttpResponseHeaders.cs
index 3a942d68d9..498ac51c41 100644
--- a/src/Servers/Kestrel/Core/src/Internal/Http/HttpResponseHeaders.cs
+++ b/src/Servers/Kestrel/Core/src/Internal/Http/HttpResponseHeaders.cs
@@ -12,7 +12,7 @@ using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
 {
-    public partial class HttpResponseHeaders : HttpHeaders
+    public sealed partial class HttpResponseHeaders : HttpHeaders
     {
         private static readonly byte[] _CrLf = new[] { (byte)'\r', (byte)'\n' };
         private static readonly byte[] _colonSpace = new[] { (byte)':', (byte)' ' };