--- a/src/spectrum/model/aloha-noack-mac-header.cc	Sun Mar 29 16:23:12 2015 +0200
+++ b/src/spectrum/model/aloha-noack-mac-header.cc	Sun Mar 29 16:22:52 2015 +0200
@@ -33,6 +33,7 @@
 {
   static TypeId tid = TypeId ("ns3::AlohaNoackMacHeader")
     .SetParent<Header> ()
+    .SetGroupName ("Spectrum")
     .AddConstructor<AlohaNoackMacHeader> ()
   ;
   return tid;