diff --git a/core/plug-in/session_timer/SessionTimer.cpp b/core/plug-in/session_timer/SessionTimer.cpp
index a714ae75..52628a90 100644
--- a/core/plug-in/session_timer/SessionTimer.cpp
+++ b/core/plug-in/session_timer/SessionTimer.cpp
@@ -262,6 +262,8 @@ bool SessionTimerFactory::checkSessionExpires(const AmSipRequest& req, AmConfigR
 
 void SessionTimer::updateTimer(AmSession* s, const AmSipRequest& req) {
 
+    DBG("Update session timer (request).");
+
   if((req.method == SIP_METH_INVITE)||(req.method == SIP_METH_UPDATE)){
     
     remote_timer_aware = 
@@ -337,11 +339,13 @@ void SessionTimer::updateTimer(AmSession* s, const AmSipRequest& req) {
   }
 }
 
-void SessionTimer::updateTimer(AmSession* s, const AmSipReply& reply) 
+void SessionTimer::updateTimer(AmSession* s, const AmSipReply& reply)
 {
   if (!session_timer_conf.getEnableSessionTimer())
     return;
 
+  DBG("Update session timer (reply).");
+
   // only update timer on positive reply, or 501 if config'd
   if (((reply.code < 200) || (reply.code >= 300)) &&
       (!(accept_501_reply && reply.code == 501)))