diff --git a/libavcodec/g729dec.c b/libavcodec/g729dec.c
index c1cdb5dcc4..be243606cf 100644
--- a/libavcodec/g729dec.c
+++ b/libavcodec/g729dec.c
@@ -224,7 +224,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
         av_log(avctx, AV_LOG_DEBUG, "Packet type: %s\n", "G.729D @ 6.4kbit/s");
     } else {
         av_log(avctx, AV_LOG_ERROR, "Packet size %d is unknown.\n", buf_size);
-        return (AVERROR_NOFMT);
+        return AVERROR_INVALIDDATA;
     }
 
     for (i=0; i < buf_size; i++)