diff --git a/libs/freetdm/src/ftmod/ftmod_r2/ftmod_r2.c b/libs/freetdm/src/ftmod/ftmod_r2/ftmod_r2.c
index 37070c45a1..e95a74bc25 100644
--- a/libs/freetdm/src/ftmod/ftmod_r2/ftmod_r2.c
+++ b/libs/freetdm/src/ftmod/ftmod_r2/ftmod_r2.c
@@ -1644,6 +1644,7 @@ static void *ftdm_r2_run(ftdm_thread_t *me, void *obj)
 	int index = 0;
 	struct timeval start, end;
 	ftdm_iterator_t *chaniter = NULL;
+	ftdm_iterator_t *citer = NULL;
 	uint32_t txqueue_size = 4;
 	short *poll_events = ftdm_malloc(sizeof(short) * span->chan_count);
 
@@ -1654,8 +1655,12 @@ static void *ftdm_r2_run(ftdm_thread_t *me, void *obj)
 	ftdm_log(FTDM_LOG_DEBUG, "OpenR2 monitor thread %lu started.\n", r2data->monitor_thread_id);
 	r2chan = NULL;
 	chaniter = ftdm_span_get_chan_iterator(span, NULL);
-	for (i = 1; chaniter; chaniter = ftdm_iterator_next(chaniter), i++) {
-		ftdmchan = ftdm_iterator_current(chaniter);
+	if (!chaniter) {
+		ftdm_log(FTDM_LOG_CRIT, "Failed to allocate channel iterator for span %s!\n", span->name);
+		goto done;
+	}
+	for (i = 1, citer = chaniter; citer; citer = ftdm_iterator_next(citer), i++) {
+		ftdmchan = ftdm_iterator_current(citer);
 		r2chan = R2CALL(ftdmchan)->r2chan;
 		openr2_chan_set_span_id(r2chan, span->span_id);
 		openr2_chan_set_idle(r2chan);
@@ -1694,9 +1699,13 @@ static void *ftdm_r2_run(ftdm_thread_t *me, void *obj)
 		 /* figure out what event to poll each channel for. POLLPRI when the channel is down,
 		  * POLLPRI|POLLIN|POLLOUT otherwise */
 		memset(poll_events, 0, sizeof(short)*span->chan_count);
-		chaniter = ftdm_span_get_chan_iterator(span, chaniter);
-		for (i = 0; chaniter; chaniter = ftdm_iterator_next(chaniter), i++) {
-			ftdmchan = ftdm_iterator_current(chaniter);
+		citer = ftdm_span_get_chan_iterator(span, chaniter);
+		if (!citer) {
+			ftdm_log(FTDM_LOG_CRIT, "Failed to allocate channel iterator for span %s!\n", span->name);
+			goto done;
+		}
+		for (i = 0; citer; citer = ftdm_iterator_next(citer), i++) {
+			ftdmchan = ftdm_iterator_current(citer);
 			r2chan = R2CALL(ftdmchan)->r2chan;
 			poll_events[i] = POLLPRI;
 			if (openr2_chan_get_read_enabled(r2chan)) {
@@ -1737,9 +1746,9 @@ static void *ftdm_r2_run(ftdm_thread_t *me, void *obj)
 
 		/* this main loop takes care of MF and CAS signaling during call setup and tear down
 		 * for every single channel in the span, do not perform blocking operations here! */
-		chaniter = ftdm_span_get_chan_iterator(span, chaniter);
-		for ( ; chaniter; chaniter = ftdm_iterator_next(chaniter)) {
-			ftdmchan = ftdm_iterator_current(chaniter);
+		citer = ftdm_span_get_chan_iterator(span, chaniter);
+		for ( ; citer; citer = ftdm_iterator_next(citer)) {
+			ftdmchan = ftdm_iterator_current(citer);
 
 			ftdm_mutex_lock(ftdmchan->mutex);
 
@@ -1766,10 +1775,11 @@ static void *ftdm_r2_run(ftdm_thread_t *me, void *obj)
 			ftdm_mutex_unlock(ftdmchan->mutex);
 		}
 	}
-	
-	chaniter = ftdm_span_get_chan_iterator(span, chaniter);
-	for ( ; chaniter; chaniter = ftdm_iterator_next(chaniter)) {
-		ftdmchan = ftdm_iterator_current(chaniter);
+
+done:	
+	citer = ftdm_span_get_chan_iterator(span, chaniter);
+	for ( ; citer; citer = ftdm_iterator_next(citer)) {
+		ftdmchan = ftdm_iterator_current(citer);
 		r2chan = R2CALL(ftdmchan)->r2chan;
 		openr2_chan_set_blocked(r2chan);
 	}