Index: mac/mac-802_11Ext.cc
--- mac/mac-802_11Ext.cc.orig
+++ mac/mac-802_11Ext.cc
@@ -162,7 +162,7 @@ void Mac802_11Ext::dump(char *) {
 
 }
 
-void Mac802_11Ext::log(char* event, char* additional) {
+void Mac802_11Ext::log(const char* event, const char* additional) {
 	if (MAC_DBG)
 		cout<<"L "<<Scheduler::instance().clock()<<" "<<index_<<" "<<"MAC"<<" "<<event<<" "<<additional
 				<<endl;