diff --git a/src/lib.rs b/src/lib.rs
index df2319e..eb70346 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -345,7 +345,7 @@ impl MovieLibrary {
         Ok(serde_json::ser::to_writer_pretty(f, &metadata)?)
     }
 
-    pub fn update_metadata(&self) -> Result<(), Error> {
+    pub fn update_metadata(&self) -> Result<Vec<String>, Error> {
         let path = Path::new(&self.root).join("metadata.json");
         // Open the file in read-only mode with buffer.
         let f = File::open(&path).context(format!("open {}", path.display()))?;
@@ -389,13 +389,14 @@ impl MovieLibrary {
             })
             .map(|(path, json)| (path, serde_json::from_str::<Value>(&json).unwrap()))
             .collect();
+        let new_movies = metadata.keys().cloned().collect();
         info!("Adding {} new videos", metadata.len());
         metadata.extend(old_metadata);
 
         let f = File::create(Path::new(&self.root).join("metadata.json"))?;
         let f = BufWriter::new(f);
         serde_json::ser::to_writer_pretty(f, &metadata)?;
-        Ok(())
+        Ok(new_movies)
     }
 
     fn iter_video_files(&self) -> impl Send + Iterator<Item = Result<PathBuf, glob::GlobError>> {
diff --git a/src/main.rs b/src/main.rs
index 24711ea..cd07120 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -87,8 +87,13 @@ enum Command {
         about = "Read full metadata file and write compact file."
     )]
     CompactMetadata,
-    #[structopt(name = "update-metadata", about = "Write metadata files")]
+    #[structopt(name = "update-metadata", about = "Write full metadata files")]
     UpdateMetadata,
+    #[structopt(
+        name = "update-compact-metadata",
+        about = "Write full metadata files and update compact file on changes"
+    )]
+    UpdateAndCompactMetadata,
 }
 
 #[derive(StructOpt)]
@@ -151,6 +156,17 @@ fn main() -> Result<(), Box<dyn Error>> {
             let lib = MovieLibrary::new(MOVIE_DIR);
             lib.update_metadata()?;
         }
+        Command::UpdateAndCompactMetadata => {
+            let lib = MovieLibrary::new(MOVIE_DIR);
+            let new_movies = lib.update_metadata()?;
+            if !new_movies.is_empty() {
+                info!(
+                    "{} new movies added, recompacting metadata",
+                    new_movies.len()
+                );
+                lib.compact_metadata()?;
+            }
+        }
     }
     Ok(())
 }