--- a/src/internet-node/ipv4-l4-demux.cc	Tue Aug 28 14:32:44 2007 +0200
+++ b/src/internet-node/ipv4-l4-demux.cc	Tue Aug 28 14:33:53 2007 +0200
@@ -84,7 +84,7 @@
 }
 
 Ptr<TraceResolver>
-Ipv4L4Demux::GetTraceResolver (void)
+Ipv4L4Demux::GetTraceResolver (void) const
 {
   Ptr<CompositeTraceResolver> resolver = Create<CompositeTraceResolver> ();
   for (L4List_t::const_iterator i = m_protocols.begin(); i != m_protocols.end(); ++i)