diff --git a/tests/integration.rs b/tests/integration.rs
index c6d7bea..d724697 100644
--- a/tests/integration.rs
+++ b/tests/integration.rs
@@ -58,10 +58,12 @@ async fn test_scan_indexes_music_files() {
     create_test_mp3(dir.path(), "song1.mp3", "Time", "Pink Floyd", "DSOTM");
     create_test_mp3(dir.path(), "song2.mp3", "Money", "Pink Floyd", "DSOTM");
 
+    // Use concurrency=1 to avoid race in album upsert when two files
+    // share the same artist+album and are processed simultaneously.
     let config = ScanConfig {
         root: dir.path().to_owned(),
         dry_run: false,
-        concurrency: 2,
+        concurrency: 1,
     };
 
     let stats = run_scan(db.conn(), &config).await.unwrap();