[corlib] Seal InternalThread

diff --git a/mcs/class/corlib/System.Threading/Thread.cs b/mcs/class/corlib/System.Threading/Thread.cs
index 00a78efe2a4e153de028ff7ac0a18cc3d3595582..d4a8d167a34246acea4db11c40161a6f6391add7 100644 (file)
--- a/mcs/class/corlib/System.Threading/Thread.cs
+++ b/mcs/class/corlib/System.Threading/Thread.cs
@@ -43,7 +43,7 @@ using System.Runtime.ConstrainedExecution;
 
 namespace System.Threading {
        [StructLayout (LayoutKind.Sequential)]
-       internal class InternalThread : CriticalFinalizerObject {
+       sealed class InternalThread : CriticalFinalizerObject {
 #pragma warning disable 169, 414, 649
                #region Sync with metadata/object-internals.h
                int lock_thread_id;