diff --git a/feeder-plugin/internetarchive-feeder/src/internetarchive.rs b/feeder-plugin/internetarchive-feeder/src/internetarchive.rs
index ec14489..30ccb5b 100644
--- a/feeder-plugin/internetarchive-feeder/src/internetarchive.rs
+++ b/feeder-plugin/internetarchive-feeder/src/internetarchive.rs
@@ -496,6 +496,7 @@ impl InternetArchivePlugin {
         fields.insert("fileType".to_string(), "audio".to_string());
         fields.insert("contentKind".to_string(), "track".to_string());
         fields.insert("domain".to_string(), "music".to_string());
+        fields.insert("workForm".to_string(), "standalone".to_string());
         fields.insert("title".to_string(), track.title.clone());
         fields.insert("album".to_string(), item.title.clone());
         fields.insert("fileName".to_string(), track.file_name.clone());
@@ -591,9 +592,11 @@ impl InternetArchivePlugin {
         let mut fields: BTreeMap<String, String> = BTreeMap::new();
         fields.insert("fileType".to_string(), "audio".to_string());
         fields.insert("contentKind".to_string(), "pack".to_string());
-        // `pack` is domain-ambiguous by construction (season pack vs album
-        // release), so the writer supplies it — METADATA_KEYS.md §1.
+        // `pack` is ambiguous on both routing axes by construction (season
+        // pack vs album release), so the writer supplies both —
+        // METADATA_KEYS.md §1. An album is a closed work: `standalone`.
         fields.insert("domain".to_string(), "music".to_string());
+        fields.insert("workForm".to_string(), "standalone".to_string());
         fields.insert("title".to_string(), item.title.clone());
         fields.insert("album".to_string(), item.title.clone());
         if !item.creator.trim().is_empty() {