diff --git a/sum.go b/sum.go
index 4fb5fa1..29d8023 100644
--- a/sum.go
+++ b/sum.go
@@ -132,7 +132,7 @@ func SumID3v2(r io.ReadSeeker) (string, error) {
 		return "", fmt.Errorf("error reading ID3v2 header: %v", err)
 	}
 
-	_, err = r.Seek(int64(header.Size)+10, os.SEEK_SET)
+	_, err = r.Seek(int64(header.Size), os.SEEK_CUR)
 	if err != nil {
 		return "", fmt.Errorf("error seeking to end of ID3V2 header: %v", err)
 	}