diff --git a/src/Servers/Kestrel/Core/src/Internal/Http/HttpHeaders.cs b/src/Servers/Kestrel/Core/src/Internal/Http/HttpHeaders.cs
index 6acb332a26..ceb017ad28 100644
--- a/src/Servers/Kestrel/Core/src/Internal/Http/HttpHeaders.cs
+++ b/src/Servers/Kestrel/Core/src/Internal/Http/HttpHeaders.cs
@@ -77,22 +77,22 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
             }
         }
 
-        protected void ThrowHeadersReadOnlyException()
+        protected static void ThrowHeadersReadOnlyException()
         {
             throw new InvalidOperationException(CoreStrings.HeadersAreReadOnly);
         }
 
-        protected void ThrowArgumentException()
+        protected static void ThrowArgumentException()
         {
             throw new ArgumentException();
         }
 
-        protected void ThrowKeyNotFoundException()
+        protected static void ThrowKeyNotFoundException()
         {
             throw new KeyNotFoundException();
         }
 
-        protected void ThrowDuplicateKeyException()
+        protected static void ThrowDuplicateKeyException()
         {
             throw new ArgumentException(CoreStrings.KeyAlreadyExists);
         }
diff --git a/src/Servers/Kestrel/Core/src/Internal/Http/HttpProtocol.cs b/src/Servers/Kestrel/Core/src/Internal/Http/HttpProtocol.cs
index 3309701e0a..72bedf1be6 100644
--- a/src/Servers/Kestrel/Core/src/Internal/Http/HttpProtocol.cs
+++ b/src/Servers/Kestrel/Core/src/Internal/Http/HttpProtocol.cs
@@ -1204,7 +1204,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http
                    statusCode != StatusCodes.Status304NotModified;
         }
 
-        private void ThrowResponseAlreadyStartedException(string value)
+        private static void ThrowResponseAlreadyStartedException(string value)
         {
             throw new InvalidOperationException(CoreStrings.FormatParameterReadOnlyAfterResponseStarted(value));
         }