diff --git a/libavformat/webmdashenc.c b/libavformat/webmdashenc.c
index 332d0466e1..1304c1a8c3 100644
--- a/libavformat/webmdashenc.c
+++ b/libavformat/webmdashenc.c
@@ -155,7 +155,8 @@ static int bitstream_switching(AVFormatContext *s, const AdaptationSet *as)
             !av_strstart(track_num->value, gold_track_num->value, NULL) ||
             gold_par->codec_id != par->codec_id ||
             gold_par->extradata_size != par->extradata_size ||
-            memcmp(gold_par->extradata, par->extradata, par->extradata_size)) {
+            (par->extradata_size > 0 &&
+             memcmp(gold_par->extradata, par->extradata, par->extradata_size))) {
             return 0;
         }
     }