diff --git a/libavformat/iff.c b/libavformat/iff.c
index edf308b135..03c4b08762 100644
--- a/libavformat/iff.c
+++ b/libavformat/iff.c
@@ -462,6 +462,8 @@ static int iff_read_packet(AVFormatContext *s,
         buf = pkt->data;
         bytestream_put_be16(&buf, 2);
         ret = avio_read(pb, buf, iff->body_size);
+        if (ret>=0 && ret < iff->body_size)
+            av_shrink_packet(pkt, ret + 2);
     } else {
         av_assert0(0);
     }