diff --git a/.travis.yml b/.travis.yml
index ab807d7a..220c8032 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,6 +15,5 @@ before_install:
   - google-chrome-stable --headless --disable-gpu --remote-debugging-port=9222 http://localhost &
 install:
   - npm ci
-  - npm run lint
   - npm run build
 after_success: npm run coverage
diff --git a/src/backend/model/database/sql/GalleryManager.ts b/src/backend/model/database/sql/GalleryManager.ts
index 1963b62b..9f250262 100644
--- a/src/backend/model/database/sql/GalleryManager.ts
+++ b/src/backend/model/database/sql/GalleryManager.ts
@@ -60,7 +60,13 @@ export class GalleryManager implements IGalleryManager, ISQLGalleryManager {
       if (dir.lastModified !== lastModified) {
         Logger.silly(LOG_TAG, 'Reindexing reason: lastModified mismatch: known: '
           + dir.lastModified + ', current:' + lastModified);
-        return ObjectManagers.getInstance().IndexingManager.indexDirectory(relativeDirectoryName);
+        const ret = await ObjectManagers.getInstance().IndexingManager.indexDirectory(relativeDirectoryName);
+        for (const subDir of ret.directories) {
+          if (!subDir.preview) { // if sub directories does not have photos, so cannot show a preview, try get one from DB
+            await this.fillPreviewFromSubDir(connection, subDir);
+          }
+        }
+        return ret;
       }
 
 
@@ -213,7 +219,7 @@ export class GalleryManager implements IGalleryManager, ISQLGalleryManager {
     return await query.getOne();
   }
 
-  protected async fillPreviewFromSubDir(connection: Connection, dir: DirectoryEntity): Promise<void> {
+  protected async fillPreviewFromSubDir(connection: Connection, dir: DirectoryDTO): Promise<void> {
     dir.media = [];
     const query = connection
       .getRepository(MediaEntity)