diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
index b2db43cb1e71857f3c14ff24c2b9629759c1e9ff..fb26d9535bc49441d61daf35d85ad39fd151891e 100644
--- a/libavformat/matroskaenc.c
+++ b/libavformat/matroskaenc.c
@@ -769,7 +769,7 @@ static int mkv_write_tracks(AVFormatContext *s)
                                         codec->codec_id == AV_CODEC_ID_VORBIS ||
                                         codec->codec_id == AV_CODEC_ID_WEBVTT)) {
             av_log(s, AV_LOG_ERROR,
-                   "Only VP8,VP9 video and Vorbis,Opus audio and WebVTT subtitles are supported for WebM.\n");
+                   "Only VP8 or VP9 video and Vorbis or Opus audio and WebVTT subtitles are supported for WebM.\n");
             return AVERROR(EINVAL);
         }