diff --git a/src/config.rs b/src/config.rs
index a3156d7..1761eca 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -90,7 +90,10 @@ struct ConfigFile {
 struct TranscodeMatchFile {
     glob: Option<String>,
     regex: Option<String>,
+
+    #[serde(default)]
     extensions: Vec<String>,
+
     to: Transcode,
 }