diff --git a/libavformat/utils.c b/libavformat/utils.c
index 4a4141e073..b4c51d135a 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1102,8 +1102,9 @@ static int av_read_frame_internal(AVFormatContext *s, AVPacket *pkt)
                     compute_pkt_fields(s, st, st->parser, pkt);
 
                     if((s->iformat->flags & AVFMT_GENERIC_INDEX) && pkt->flags & AV_PKT_FLAG_KEY){
+                        int64_t pos= (st->parser->flags & PARSER_FLAG_COMPLETE_FRAMES) ? pkt->pos : st->parser->frame_offset;
                         ff_reduce_index(s, st->index);
-                        av_add_index_entry(st, st->parser->frame_offset, pkt->dts,
+                        av_add_index_entry(st, pos, pkt->dts,
                                            0, 0, AVINDEX_KEYFRAME);
                     }