diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
index 64f6ea8c0e..47772a4998 100644
--- a/libavformat/mp3dec.c
+++ b/libavformat/mp3dec.c
@@ -109,8 +109,8 @@ static int mp3_parse_vbr_tags(AVFormatContext *s, AVStream *st, int64_t base)
         if(avio_rb16(s->pb) == 1) {
             /* skip delay and quality */
             avio_skip(s->pb, 4);
-            frames = avio_rb32(s->pb);
             size = avio_rb32(s->pb);
+            frames = avio_rb32(s->pb);
         }
     }