diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c
index 7eaecf0469..e3b3e5ac32 100644
--- a/libavformat/rmdec.c
+++ b/libavformat/rmdec.c
@@ -972,4 +972,5 @@ AVInputFormat ff_rdt_demuxer = {
     .long_name      = NULL_IF_CONFIG_SMALL("RDT demuxer"),
     .priv_data_size = sizeof(RMDemuxContext),
     .read_close     = rm_read_close,
+    .flags          = AVFMT_NOFILE,
 };