diff --git a/src/lib.rs b/src/lib.rs
index 28ea101..df2319e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -190,6 +190,7 @@ pub struct CompactMetadata {
     size: usize,
     video: Vec<VideoFormat>,
     audio: Vec<AudioFormat>,
+    #[serde(skip_serializing_if = "Vec::is_empty")]
     subtitle: Vec<SubtitleFormat>,
 }