diff --git a/libavformat/mpc8.c b/libavformat/mpc8.c
index a15dc25a69..722d0ee05f 100644
--- a/libavformat/mpc8.c
+++ b/libavformat/mpc8.c
@@ -223,6 +223,10 @@ static int mpc8_read_header(AVFormatContext *s)
     while(!avio_feof(pb)){
         pos = avio_tell(pb);
         mpc8_get_chunk_header(pb, &tag, &size);
+        if (size < 0) {
+            av_log(s, AV_LOG_ERROR, "Invalid chunk length\n");
+            return AVERROR_INVALIDDATA;
+        }
         if(tag == TAG_STREAMHDR)
             break;
         mpc8_handle_chunk(s, tag, pos, size);