diff --git a/mcs/class/System.Web/System.Web/HttpHeaderCollection.cs b/mcs/class/System.Web/System.Web/HttpHeaderCollection.cs
index 6bc6917339bfe..b015d16ef6ec4 100644
--- a/mcs/class/System.Web/System.Web/HttpHeaderCollection.cs
+++ b/mcs/class/System.Web/System.Web/HttpHeaderCollection.cs
@@ -34,6 +34,10 @@ sealed class HttpHeaderCollection : NameValueCollection
 	{
 		bool? headerCheckingEnabled;
 
+		public HttpHeaderCollection () : base (StringComparer.OrdinalIgnoreCase)
+		{
+		}
+
 		bool HeaderCheckingEnabled {
 			get {
 				if (headerCheckingEnabled == null)
diff --git a/mcs/class/System.Web/System.Web/HttpResponse.cs b/mcs/class/System.Web/System.Web/HttpResponse.cs
index ac432ab3da3b5..053d20c9c58b9 100644
--- a/mcs/class/System.Web/System.Web/HttpResponse.cs
+++ b/mcs/class/System.Web/System.Web/HttpResponse.cs
@@ -510,27 +510,27 @@ public void AppendHeader (string name, string value)
 			if (headers_sent)
 				throw new HttpException ("Headers have been already sent");
 #if !TARGET_J2EE
-			if (String.Compare (name, "content-length", true, Helpers.InvariantCulture) == 0){
+			if (String.Compare (name, "content-length", StringComparison.OrdinalIgnoreCase) == 0){
 				content_length = (long) UInt64.Parse (value);
 				use_chunked = false;
 				return;
 			}
 #endif
 
-			if (String.Compare (name, "content-type", true, Helpers.InvariantCulture) == 0){
+			if (String.Compare (name, "content-type", StringComparison.OrdinalIgnoreCase) == 0){
 				ContentType = value;
 				return;
 			}
 
 #if !TARGET_J2EE
-			if (String.Compare (name, "transfer-encoding", true, Helpers.InvariantCulture) == 0){
+			if (String.Compare (name, "transfer-encoding", StringComparison.OrdinalIgnoreCase) == 0){
 				transfer_encoding = value;
 				use_chunked = false;
 				return;
 			}
 #endif
 
-			if (String.Compare (name, "cache-control", true, Helpers.InvariantCulture) == 0){
+			if (String.Compare (name, "cache-control", StringComparison.OrdinalIgnoreCase) == 0){
 				user_cache_control = value;
 				return;
 			}