--- main/rtp_engine.c	(Asterisk 13.38.3)
+++ main/rtp_engine.c	(working copy)
@@ -721,8 +721,11 @@
 void ast_rtp_codecs_payloads_copy(struct ast_rtp_codecs *src, struct ast_rtp_codecs *dest, struct ast_rtp_instance *instance)
 {
 	int i;
 
+	ast_rtp_codecs_payloads_destroy(dest);
+	ast_rtp_codecs_payloads_initialize(dest);
+
 	ast_rwlock_wrlock(&dest->codecs_lock);
 
 	/* Deadlock avoidance because of held write lock. */
 	while (ast_rwlock_tryrdlock(&src->codecs_lock)) {