diff --git a/nestegg/include/nestegg/nestegg.h b/nestegg/include/nestegg/nestegg.h
index 7447d141d..6510694ba 100644
--- a/nestegg/include/nestegg/nestegg.h
+++ b/nestegg/include/nestegg/nestegg.h
@@ -67,6 +67,7 @@ extern "C" {
 
 #define NESTEGG_CODEC_VP8    0 /**< Track uses Google On2 VP8 codec. */
 #define NESTEGG_CODEC_VORBIS 1 /**< Track uses Xiph Vorbis codec. */
+#define NESTEGG_CODEC_VP9    2 /**< Track uses Google On2 VP9 codec. */
 
 #define NESTEGG_SEEK_SET 0 /**< Seek offset relative to beginning of stream. */
 #define NESTEGG_SEEK_CUR 1 /**< Seek offset relative to current position in stream. */
diff --git a/nestegg/src/nestegg.c b/nestegg/src/nestegg.c
index cc87788fe..ae87e8f8f 100644
--- a/nestegg/src/nestegg.c
+++ b/nestegg/src/nestegg.c
@@ -127,6 +127,7 @@ enum ebml_type_enum {
 
 /* Track IDs */
 #define TRACK_ID_VP8            "V_VP8"
+#define TRACK_ID_VP9            "V_VP9"
 #define TRACK_ID_VORBIS         "A_VORBIS"
 
 enum vint_mask {
@@ -1669,6 +1670,9 @@ nestegg_track_codec_id(nestegg * ctx, unsigned int track)
   if (strcmp(codec_id, TRACK_ID_VP8) == 0)
     return NESTEGG_CODEC_VP8;
 
+  if (strcmp(codec_id, TRACK_ID_VP9) == 0)
+    return NESTEGG_CODEC_VP9;
+
   if (strcmp(codec_id, TRACK_ID_VORBIS) == 0)
     return NESTEGG_CODEC_VORBIS;
 
diff --git a/vpxdec.c b/vpxdec.c
index aa3f342d8..f7281a4ef 100644
--- a/vpxdec.c
+++ b/vpxdec.c
@@ -537,6 +537,7 @@ file_is_webm(struct input_ctx *input,
              unsigned int     *fps_num) {
   unsigned int i, n;
   int          track_type = -1;
+  int          codec_id;
 
   nestegg_io io = {nestegg_read_cb, nestegg_seek_cb, nestegg_tell_cb, 0};
   nestegg_video_params params;
@@ -557,8 +558,13 @@ file_is_webm(struct input_ctx *input,
       goto fail;
   }
 
-  if (nestegg_track_codec_id(input->nestegg_ctx, i) != NESTEGG_CODEC_VP8) {
-    fprintf(stderr, "Not VP8 video, quitting.\n");
+  codec_id = nestegg_track_codec_id(input->nestegg_ctx, i);
+  if (codec_id == NESTEGG_CODEC_VP8) {
+    *fourcc = VP8_FOURCC;
+  } else if (codec_id == NESTEGG_CODEC_VP9) {
+    *fourcc = VP9_FOURCC;
+  } else {
+    fprintf(stderr, "Not VPx video, quitting.\n");
     exit(1);
   }
 
@@ -569,7 +575,6 @@ file_is_webm(struct input_ctx *input,
 
   *fps_den = 0;
   *fps_num = 0;
-  *fourcc = VP8_FOURCC;
   *width = params.width;
   *height = params.height;
   return 1;
diff --git a/vpxenc.c b/vpxenc.c
index 68b7a5c25..83400b9c5 100644
--- a/vpxenc.c
+++ b/vpxenc.c
@@ -86,6 +86,8 @@ static size_t wrap_fwrite(const void *ptr, size_t size, size_t nmemb,
 
 static const char *exec_name;
 
+#define VP8_FOURCC (0x00385056)
+#define VP9_FOURCC (0x00395056)
 static const struct codec_item {
   char const              *name;
   const vpx_codec_iface_t *(*iface)(void);
@@ -93,14 +95,14 @@ static const struct codec_item {
   unsigned int             fourcc;
 } codecs[] = {
 #if CONFIG_VP8_ENCODER && CONFIG_VP8_DECODER
-  {"vp8", &vpx_codec_vp8_cx, &vpx_codec_vp8_dx, 0x30385056},
+  {"vp8", &vpx_codec_vp8_cx, &vpx_codec_vp8_dx, VP8_FOURCC},
 #elif CONFIG_VP8_ENCODER && !CONFIG_VP8_DECODER
-  {"vp8", &vpx_codec_vp8_cx, NULL, 0x30385056},
+  {"vp8", &vpx_codec_vp8_cx, NULL, VP8_FOURCC},
 #endif
 #if CONFIG_VP9_ENCODER && CONFIG_VP9_DECODER
-  {"vp9", &vpx_codec_vp9_cx, &vpx_codec_vp9_dx, 0x30395056},
+  {"vp9", &vpx_codec_vp9_cx, &vpx_codec_vp9_dx, VP9_FOURCC},
 #elif CONFIG_VP9_ENCODER && !CONFIG_VP9_DECODER
-  {"vp9", &vpx_codec_vp9_cx, NULL, 0x30395056},
+  {"vp9", &vpx_codec_vp9_cx, NULL, VP9_FOURCC},
 #endif
 };
 
@@ -663,7 +665,8 @@ static void
 write_webm_file_header(EbmlGlobal                *glob,
                        const vpx_codec_enc_cfg_t *cfg,
                        const struct vpx_rational *fps,
-                       stereo_format_t            stereo_fmt) {
+                       stereo_format_t            stereo_fmt,
+                       unsigned int               fourcc) {
   {
     EbmlLoc start;
     Ebml_StartSubElement(glob, &start, EBML);
@@ -696,7 +699,8 @@ write_webm_file_header(EbmlGlobal                *glob,
         glob->track_id_pos = ftello(glob->stream);
         Ebml_SerializeUnsigned32(glob, TrackUID, trackID);
         Ebml_SerializeUnsigned(glob, TrackType, 1);
-        Ebml_SerializeString(glob, CodecID, "V_VP8");
+        Ebml_SerializeString(glob, CodecID,
+                             fourcc == VP8_FOURCC ? "V_VP8" : "V_VP9");
         {
           unsigned int pixelWidth = cfg->g_w;
           unsigned int pixelHeight = cfg->g_h;
@@ -2028,7 +2032,8 @@ static void open_output_file(struct stream_state *stream,
     stream->ebml.stream = stream->file;
     write_webm_file_header(&stream->ebml, &stream->config.cfg,
                            &global->framerate,
-                           stream->config.stereo_fmt);
+                           stream->config.stereo_fmt,
+                           global->codec->fourcc);
   } else
     write_ivf_file_header(stream->file, &stream->config.cfg,
                           global->codec->fourcc, 0);