diff --git a/asterisk/IMS_ConnectionHandler.ttcn b/asterisk/IMS_ConnectionHandler.ttcn
index 0d11922..091f5da 100644
--- a/asterisk/IMS_ConnectionHandler.ttcn
+++ b/asterisk/IMS_ConnectionHandler.ttcn
@@ -503,7 +503,7 @@
 		*/
 		authorization := f_tr_Authorization_AKAv1MD5(valueof(wwwAuthenticate),
 							     g_pars.user & "@" & g_pars.realm,
-							     f_sip_SipUrl_to_str(g_pars.registrar_sip_record.addr.nameAddr.addrSpec));
+							     f_sip_SipUrl_to_str(g_pars.registrar_sip_req_uri));
 		/* TODO: match Authorization from above: */
 		exp_req :=
 		tr_SIP_REGISTER(g_pars.registrar_sip_req_uri,