diff --git a/src/modules/ims_isc/ims_isc_mod.c b/src/modules/ims_isc/ims_isc_mod.c
index e0f7b940ee4..4618ca7db15 100644
--- a/src/modules/ims_isc/ims_isc_mod.c
+++ b/src/modules/ims_isc/ims_isc_mod.c
@@ -224,6 +224,8 @@ int isc_match_filter(struct sip_msg *msg, char *str1, udomain_t* d) {
     //sometimes s is populated by an ims_getter method cscf_get_terminating_user that alloc memory that must be free-ed at the end
     int free_s = 0;
 
+    //the callback from the Cx interface in case of unreg terminating initial message is a FAILURE_ROUTE. Hence we need an addl. flag
+    int firstflag = 0;
 
     int ret = ISC_RETURN_FALSE;
     isc_mark new_mark, old_mark;
@@ -245,9 +247,10 @@ int isc_match_filter(struct sip_msg *msg, char *str1, udomain_t* d) {
         LM_DBG("Message returned s=%d;h=%d;d=%d;a=%.*s\n", old_mark.skip, old_mark.handling, old_mark.direction, old_mark.aor.len, old_mark.aor.s);
     } else {
         LM_DBG("Starting triggering\n");
+        firstflag = 1;
     }
 
-    if (is_route_type(FAILURE_ROUTE)) {
+    if (is_route_type(FAILURE_ROUTE) && !firstflag) {
         /* need to find the handling for the failed trigger */
         if (dir == DLG_MOBILE_ORIGINATING) {
             k = cscf_get_originating_user(msg, &s);
@@ -345,7 +348,7 @@ int isc_match_filter(struct sip_msg *msg, char *str1, udomain_t* d) {
                 new_mark.skip = m->index + 1;
                 new_mark.handling = m->default_handling;
                 new_mark.aor = s;
-                ret = isc_forward(msg, m, &new_mark);
+                ret = isc_forward(msg, m, &new_mark, firstflag);
                 isc_free_match(m);
                 goto done;
             }
@@ -383,7 +386,7 @@ int isc_match_filter(struct sip_msg *msg, char *str1, udomain_t* d) {
                 new_mark.skip = m->index + 1;
                 new_mark.handling = m->default_handling;
                 new_mark.aor = s;
-                ret = isc_forward(msg, m, &new_mark);
+                ret = isc_forward(msg, m, &new_mark, firstflag);
                 isc_free_match(m);
                 goto done;
             }
diff --git a/src/modules/ims_isc/isc.c b/src/modules/ims_isc/isc.c
index 3d1fdf5c46b..a095e054e77 100644
--- a/src/modules/ims_isc/isc.c
+++ b/src/modules/ims_isc/isc.c
@@ -56,7 +56,7 @@
  * @param mark  - the isc_mark that should be used to mark the message
  * @returns #ISC_RETURN_TRUE if OK, #ISC_RETURN_ERROR if not
  */
-int isc_forward(struct sip_msg *msg, isc_match *m, isc_mark *mark) {
+int isc_forward(struct sip_msg *msg, isc_match *m, isc_mark *mark, int firstflag) {
 	struct cell *t;
 	unsigned int hash, label;
 	ticks_t fr_timeout, fr_inv_timeout;
@@ -75,7 +75,7 @@ int isc_forward(struct sip_msg *msg, isc_match *m, isc_mark *mark) {
 	memcpy(msg->dst_uri.s, m->server_name.s, m->server_name.len);
 
 	/* append branch if last trigger failed */
-	if (is_route_type(FAILURE_ROUTE))
+	if (is_route_type(FAILURE_ROUTE) && !firstflag)
 		append_branch(msg, &(msg->first_line.u.request.uri), &(msg->dst_uri), 0, Q_UNSPECIFIED, 0, 0, 0, 0, 0, 0);
 
 	// Determines the tm transaction identifiers.
diff --git a/src/modules/ims_isc/isc.h b/src/modules/ims_isc/isc.h
index 8c3715e347d..ac012162fd3 100644
--- a/src/modules/ims_isc/isc.h
+++ b/src/modules/ims_isc/isc.h
@@ -66,7 +66,7 @@ extern int isc_fr_inv_timeout;		/**< default ISC INVITE response timeout in ms *
 /**	SIP Status Code to send to client on Session Termination because AS did not respond */
 
 
-int isc_forward( struct sip_msg *msg, isc_match *m,isc_mark *mark);
+int isc_forward( struct sip_msg *msg, isc_match *m,isc_mark *mark, int firstflag);
 
 
 #endif