diff --git a/libavformat/md5enc.c b/libavformat/md5enc.c
index 8e87f095c9..e1a53684b6 100644
--- a/libavformat/md5enc.c
+++ b/libavformat/md5enc.c
@@ -107,7 +107,8 @@ AVOutputFormat ff_md5_muxer = {
     .write_header      = write_header,
     .write_packet      = write_packet,
     .write_trailer     = write_trailer,
-    .flags             = AVFMT_NOTIMESTAMPS,
+    .flags             = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT |
+                         AVFMT_TS_NEGATIVE,
     .priv_class        = &md5enc_class,
 };
 #endif