diff --git a/src/fr/inrialpes/exmo/align/service/AServProtocolManager.java b/src/fr/inrialpes/exmo/align/service/AServProtocolManager.java
index 319cd3c122d7a814a8d652fdbd5b2acc27ee5def..df1eba829207485948da89680cb4443df714c7d0 100644
--- a/src/fr/inrialpes/exmo/align/service/AServProtocolManager.java
+++ b/src/fr/inrialpes/exmo/align/service/AServProtocolManager.java
@@ -1026,10 +1026,10 @@ public class AServProtocolManager implements Service {
 	    pretty = noo.getExtension( Namespace.EXT.uri, Annotations.PRETTY ) + "/trimmed";
 	}
 	noo = noo.clone();
-	noo.setExtension( Namespace.EXT.uri, Annotations.PRETTY, pretty );
 	// trim
     	try {
 	    noo.trim( method, threshold );
+	    noo.setExtension( Namespace.EXT.uri, Annotations.PRETTY, pretty );
 	} catch (AlignmentException e) {
     	    return new ErrorMsg( params, newId(), serverId,"Network alignment error" );
     	}