diff --git a/src/muxer/tvh/mkmux.c b/src/muxer/tvh/mkmux.c
index 7d620b20..c6ed8731 100644
--- a/src/muxer/tvh/mkmux.c
+++ b/src/muxer/tvh/mkmux.c
@@ -1159,7 +1159,7 @@ mk_mux_write_pkt(mk_mux_t *mkm, th_pkt_t *pkt)
       break;
   }
   
-  if(t == NULL) {
+  if(i >= mkm->ntracks) {
     pkt_ref_dec(pkt);
     return mkm->error;
   }