diff --git a/mRemoteNG/Connection/Protocol/ProtocolBase.cs b/mRemoteNG/Connection/Protocol/ProtocolBase.cs
index a257133c0..37ba0c97e 100644
--- a/mRemoteNG/Connection/Protocol/ProtocolBase.cs
+++ b/mRemoteNG/Connection/Protocol/ProtocolBase.cs
@@ -203,6 +203,10 @@ namespace mRemoteNG.Connection.Protocol
 
         private void DisposeInterface()
         {
+            if (_interfaceControl.IsDisposed)
+            {
+                return;
+            }
             if (_interfaceControl.InvokeRequired)
             {
                 var s = new DisposeInterfaceCB(DisposeInterface);