diff --git a/libavformat/rtpproto.c b/libavformat/rtpproto.c
index bef8f1aa1e..88a39796a9 100644
--- a/libavformat/rtpproto.c
+++ b/libavformat/rtpproto.c
@@ -437,7 +437,7 @@ static int rtp_write(URLContext *h, const uint8_t *buf, int size)
     if (size < 2)
         return AVERROR(EINVAL);
 
-    if (buf[0] != (RTP_VERSION << 6))
+    if ((buf[0] & 0xc0) != (RTP_VERSION << 6))
         av_log(h, AV_LOG_WARNING, "Data doesn't look like RTP packets, "
                                   "make sure the RTP muxer is used\n");