diff --git a/mcs/class/System.ServiceModel/System.ServiceModel/NetTcpSecurity.cs b/mcs/class/System.ServiceModel/System.ServiceModel/NetTcpSecurity.cs
index c5065a185864e2cf6ed97c42ea0097651696f70e..18646251c27de899a3354cf1a2045638985cf3e6 100644
--- a/mcs/class/System.ServiceModel/System.ServiceModel/NetTcpSecurity.cs
+++ b/mcs/class/System.ServiceModel/System.ServiceModel/NetTcpSecurity.cs
@@ -33,6 +33,12 @@ namespace System.ServiceModel
 {
 	public sealed class NetTcpSecurity
 	{
+#if NET_4_0
+		public NetTcpSecurity ()
+		{
+		}
+#endif
+
 		internal NetTcpSecurity (SecurityMode mode)
 		{
 			this.mode = mode;