diff --git a/libavformat/mov.c b/libavformat/mov.c
index f22a407f49..df9640fa6d 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -6002,6 +6002,7 @@ static int mov_seek_stream(AVFormatContext *s, AVStream *st, int64_t timestamp,
     }
 
     /* adjust stsd index */
+    if (sc->chunk_count) {
     time_sample = 0;
     for (i = 0; i < sc->stsc_count; i++) {
         int next = time_sample + mov_get_stsc_samples(sc, i);
@@ -6012,6 +6013,7 @@ static int mov_seek_stream(AVFormatContext *s, AVStream *st, int64_t timestamp,
         }
         time_sample = next;
     }
+    }
 
     ret = mov_seek_auxiliary_info(s, sc);
     if (ret < 0) {