diff --git a/plugins/contracts/org.polarsys.chess.contracts.chessextension/src/org/polarsys/chess/contracts/chessextension/listeners/PapyrusModelListener.java b/plugins/contracts/org.polarsys.chess.contracts.chessextension/src/org/polarsys/chess/contracts/chessextension/listeners/PapyrusModelListener.java
index 7c02df0d40c6a779db13cb7991bac3cc0ee5f99f..b695bf1e6d589752b79cc8a4c04d5a7bf3701293 100644
--- a/plugins/contracts/org.polarsys.chess.contracts.chessextension/src/org/polarsys/chess/contracts/chessextension/listeners/PapyrusModelListener.java
+++ b/plugins/contracts/org.polarsys.chess.contracts.chessextension/src/org/polarsys/chess/contracts/chessextension/listeners/PapyrusModelListener.java
@@ -48,8 +48,10 @@ public class PapyrusModelListener implements IPapyrusListener {
 	@Override
 	public void notifyChanged(Notification notification) {
 		Object notifier = notification.getNotifier();
-		if(notifier instanceof Class){
+		
+		if((notifier instanceof Class)&(PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage().isEditorAreaVisible())){
 			Class cblock = (Class) notifier;
+			
 			if(notification.getEventType() == StereotypeExtensionNotification.STEREOTYPE_APPLIED_TO_ELEMENT){
 				if(cblock.getAppliedStereotype(CONTRACT) != null){