diff --git a/demux/demux.h b/demux/demux.h
index e882e90da8..2c1e3a20fa 100644
--- a/demux/demux.h
+++ b/demux/demux.h
@@ -174,7 +174,7 @@ typedef struct demuxer {
     int64_t filepos;  // input stream current pos.
     char *filename;  // same as stream->url
     bool seekable;
-    bool partially_seekable; // implies seekable=true
+    bool partially_seekable; // true if _maybe_ seekable; implies seekable=true
     double start_time;
     // File format allows PTS resets (even if the current file is without)
     bool ts_resets_possible;
diff --git a/demux/demux_timeline.c b/demux/demux_timeline.c
index 0c6c3986cc..92cf1e6fcf 100644
--- a/demux/demux_timeline.c
+++ b/demux/demux_timeline.c
@@ -344,7 +344,7 @@ static int d_open(struct demuxer *demuxer, enum demux_check check)
     print_timeline(demuxer);
 
     demuxer->seekable = true;
-    demuxer->partially_seekable = true;
+    demuxer->partially_seekable = false;
 
     demuxer->filetype = meta->filetype ? meta->filetype : meta->desc->name;