diff --git a/gst/matroska/matroska-mux.c b/gst/matroska/matroska-mux.c
index b5b94854fe..1f5142871c 100644
--- a/gst/matroska/matroska-mux.c
+++ b/gst/matroska/matroska-mux.c
@@ -2881,7 +2881,7 @@ gst_matroska_mux_start (GstMatroskaMux * mux)
     thepad = collect_pad->collect.pad;
 
     if (gst_pad_is_linked (thepad) && gst_pad_is_active (thepad) &&
-        collect_pad->track->codec_id != 0) {
+        collect_pad->track->codec_id != NULL) {
       collect_pad->track->num = tracknum++;
       child = gst_ebml_write_master_start (ebml, GST_MATROSKA_ID_TRACKENTRY);
       gst_matroska_mux_track_header (mux, collect_pad->track);
@@ -3544,12 +3544,11 @@ gst_matroska_mux_write_data (GstMatroskaMux * mux, GstMatroskaPad * collect_pad,
   }
 
   /* for dirac we have to queue up everything up to a picture unit */
-  if (!g_strcmp0 (collect_pad->track->codec_id,
-          GST_MATROSKA_CODEC_ID_VIDEO_DIRAC)) {
+  if (!strcmp (collect_pad->track->codec_id, GST_MATROSKA_CODEC_ID_VIDEO_DIRAC)) {
     buf = gst_matroska_mux_handle_dirac_packet (mux, collect_pad, buf);
     if (!buf)
       return GST_FLOW_OK;
-  } else if (!g_strcmp0 (collect_pad->track->codec_id,
+  } else if (!strcmp (collect_pad->track->codec_id,
           GST_MATROSKA_CODEC_ID_VIDEO_PRORES)) {
     /* Remove the 'Frame container atom' header' */
     buf = gst_buffer_make_writable (buf);
@@ -3820,6 +3819,12 @@ gst_matroska_mux_handle_buffer (GstCollectPads * pads, GstCollectData * data,
     goto exit;
   }
 
+  if (best->track->codec_id == NULL) {
+    GST_ERROR_OBJECT (best->collect.pad, "No codec-id for pad");
+    ret = GST_FLOW_NOT_NEGOTIATED;
+    goto exit;
+  }
+
   /* if we have a best stream, should also have a buffer */
   g_assert (buf);