diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 626c0d0d68..d2812b3984 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -583,7 +583,7 @@ void av_set_pts_info(AVStream *s, int pts_wrap_bits,
 #define AVSEEK_FLAG_BYTE     2 ///< seeking based on position in bytes
 
 int av_find_default_stream_index(AVFormatContext *s);
-int av_index_search_timestamp(AVStream *st, int timestamp, int flags);
+int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags);
 int av_add_index_entry(AVStream *st,
                        int64_t pos, int64_t timestamp, int distance, int flags);
 int av_seek_frame_binary(AVFormatContext *s, int stream_index, int64_t target_ts, int flags);
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 6178d15ffe..6b3bd5db48 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1046,7 +1046,8 @@ static int is_raw_stream(AVFormatContext *s)
  *                 then it will be >=
  * @return < 0 if no such timestamp could be found
  */
-int av_index_search_timestamp(AVStream *st, int wanted_timestamp, int backward)
+int av_index_search_timestamp(AVStream *st, int64_t wanted_timestamp,
+                              int backward)
 {
     AVIndexEntry *entries= st->index_entries;
     int nb_entries= st->nb_index_entries;