diff --git a/src/muxer/muxer_libav.c b/src/muxer/muxer_libav.c
index 9160af68..32f9cba1 100644
--- a/src/muxer/muxer_libav.c
+++ b/src/muxer/muxer_libav.c
@@ -403,6 +403,8 @@ lav_muxer_write_pkt(muxer_t *m, streaming_message_type_t smt, void *data)
 
     if(st->id != pkt->pkt_componentindex)
       continue;
+    if(pkt->pkt_payload == NULL)
+      continue;
 
     av_init_packet(&packet);
 
diff --git a/src/muxer/tvh/mkmux.c b/src/muxer/tvh/mkmux.c
index 6bc62a08..aaad9b04 100644
--- a/src/muxer/tvh/mkmux.c
+++ b/src/muxer/tvh/mkmux.c
@@ -1188,7 +1188,7 @@ mk_mux_write_pkt(mk_mux_t *mkm, th_pkt_t *pkt)
       break;
   }
   
-  if(i >= mkm->ntracks) {
+  if(i >= mkm->ntracks || pkt->pkt_payload == NULL) {
     pkt_ref_dec(pkt);
     return mkm->error;
   }