diff --git a/lib/thumbnailprovider/thumbnailprovider.cpp b/lib/thumbnailprovider/thumbnailprovider.cpp
--- a/lib/thumbnailprovider/thumbnailprovider.cpp
+++ b/lib/thumbnailprovider/thumbnailprovider.cpp
@@ -536,8 +536,11 @@
         return;
     }
     LOG(mCurrentItem.url());
-    QSize size;
-    emit thumbnailLoaded(item, pixmap, size, mOriginalFileSize);
+    const int requestedSize = ThumbnailGroup::pixelSize(mThumbnailGroup);
+    const QPixmap preview = qMax(pixmap.width(), pixmap.height()) < requestedSize
+        ? pixmap.scaled(requestedSize, requestedSize,  Qt::KeepAspectRatio, Qt::SmoothTransformation)
+        : pixmap;
+    emit thumbnailLoaded(item, preview, preview.size(), mOriginalFileSize);
 }
 
 void ThumbnailProvider::emitThumbnailLoaded(const QImage& img, const QSize& size)