--- a/src/visualizer/model/pyviz.cc	Sun Mar 29 16:43:22 2015 +0200
+++ b/src/visualizer/model/pyviz.cc	Sun Mar 29 16:46:05 2015 +0200
@@ -85,6 +85,7 @@
 {
   static TypeId tid = TypeId ("ns3::PyVizPacketTag")
     .SetParent<Tag> ()
+    .SetGroupName ("Visualizer")
     .AddConstructor<PyVizPacketTag> ()
   ;
   return tid;