diff --git a/OpenRA.Game/Server/Connection.cs b/OpenRA.Game/Server/Connection.cs
index 4bb1d76aa5..008d4d78ce 100644
--- a/OpenRA.Game/Server/Connection.cs
+++ b/OpenRA.Game/Server/Connection.cs
@@ -21,7 +21,7 @@ using System.Threading;
 
 namespace OpenRA.Server
 {
-	public class Connection : IDisposable
+	public sealed class Connection : IDisposable
 	{
 		public const int MaxOrderLength = 131072;