diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 9e47a6f7b4..babcf24482 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -82,6 +82,7 @@ void av_register_all(void)
     REGISTER_DEMUXER  (FOURXM, fourxm);
     REGISTER_MUXER    (FRAMECRC, framecrc);
     REGISTER_MUXDEMUX (GIF, gif);
+    REGISTER_DEMUXER  (GSM, gsm);
     REGISTER_MUXDEMUX (GXF, gxf);
     REGISTER_MUXDEMUX (H261, h261);
     REGISTER_MUXDEMUX (H263, h263);
diff --git a/libavformat/raw.c b/libavformat/raw.c
index 718727e2d9..ac44b845ab 100644
--- a/libavformat/raw.c
+++ b/libavformat/raw.c
@@ -496,6 +496,19 @@ AVInputFormat aac_demuxer = {
     .value = CODEC_ID_AAC,
 };
 
+AVInputFormat gsm_demuxer = {
+    "gsm",
+    "GSM",
+    0,
+    NULL,
+    audio_read_header,
+    raw_read_partial_packet,
+    raw_read_close,
+    .flags= AVFMT_GENERIC_INDEX,
+    .extensions = "gsm",
+    .value = CODEC_ID_GSM,
+};
+
 #ifdef CONFIG_ROQ_MUXER
 AVOutputFormat roq_muxer =
 {