diff --git a/backend/app.go b/backend/app.go
index bb032ce..66f5911 100644
--- a/backend/app.go
+++ b/backend/app.go
@@ -206,8 +206,10 @@ func (yj *YellowJacketApp) OnStartup(ctx context.Context) {
 		},
 		PostScan: func() {
 			yj.playlist.RestoreAllPlaylists()
-			// Restart the index build now that the scan is done.
-			yj.explore.StartIndexBuild()
+			// DON'T restart the index build here — queued
+			// library scans may still be running.  The index
+			// build starts after ALL scans complete (via the
+			// scan hooks below).
 		},
 	})
 
@@ -215,6 +217,9 @@ func (yj *YellowJacketApp) OnStartup(ctx context.Context) {
 	// phantom tracks after each library scan completes.
 	yj.library.SetScanHooks(library.ScanHooks{
 		ResolvePhantoms: yj.playlist.ResolvePhantomTracksAfterScan,
+		OnAllScansComplete: func() {
+			yj.explore.StartIndexBuild()
+		},
 	})
 
 	// Wire removal hooks so the library can stop playback and
@@ -329,8 +334,11 @@ func (yj *YellowJacketApp) OnDomReady(ctx context.Context) {
 			yj.logger.Error("soft scan failed", "err", err)
 		}
 
-		// Start the explore search index build AFTER the library
-		// scan completes so they don't fight for DB access.
-		yj.explore.StartIndexBuild()
+		// If no scans were queued (library unchanged), start the
+		// index build directly.  If scans WERE queued, the
+		// OnAllScansComplete hook starts it after they finish.
+		if yj.library.GetScanQueueLength() == 0 && !yj.library.IsScanActive() {
+			yj.explore.StartIndexBuild()
+		}
 	}()
 }
diff --git a/backend/library/library.go b/backend/library/library.go
index dc4b5cc..e30b015 100644
--- a/backend/library/library.go
+++ b/backend/library/library.go
@@ -79,6 +79,9 @@ type ScanHooks struct {
 	// ResolvePhantoms re-links phantom playlist tracks whose
 	// files now exist in the library after scanning.
 	ResolvePhantoms func()
+	// OnAllScansComplete runs after ALL queued scans finish
+	// (queue drained).
+	OnAllScansComplete func()
 }
 
 // Library manages scanning and querying the music collection.
diff --git a/backend/library/scan_queue.go b/backend/library/scan_queue.go
index fc46018..3c3e3b4 100644
--- a/backend/library/scan_queue.go
+++ b/backend/library/scan_queue.go
@@ -254,7 +254,12 @@ func (l *Library) drainQueue() {
 	l.currentScanLibraryID = 0
 	l.currentScanLibraryName = ""
 	l.scanActive = false
+	hooks := l.scanHooks
 	l.mu.Unlock()
 
 	runtime.EventsEmit(l.ctx, events.LibraryScanQueueDrained)
+
+	if hooks.OnAllScansComplete != nil {
+		hooks.OnAllScansComplete()
+	}
 }