diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index bba42782e0..d8f854c8a5 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -2071,7 +2071,8 @@ static int mov_write_ilst_tag(AVIOContext *pb, MOVMuxContext *mov,
     mov_write_string_metadata(s, pb, "\251wrt", "composer" , 1);
     mov_write_string_metadata(s, pb, "\251alb", "album"    , 1);
     mov_write_string_metadata(s, pb, "\251day", "date"     , 1);
-    mov_write_string_tag(pb, "\251too", LIBAVFORMAT_IDENT, 0, 1);
+    if (!mov_write_string_metadata(s, pb, "\251too", "encoding_tool", 1))
+        mov_write_string_tag(pb, "\251too", LIBAVFORMAT_IDENT, 0, 1);
     mov_write_string_metadata(s, pb, "\251cmt", "comment"  , 1);
     mov_write_string_metadata(s, pb, "\251gen", "genre"    , 1);
     mov_write_string_metadata(s, pb, "\251cpy", "copyright", 1);