diff --git a/src/imageviewwidget.cpp b/src/imageviewwidget.cpp
index 7889a96..1f8b39e 100644
--- a/src/imageviewwidget.cpp
+++ b/src/imageviewwidget.cpp
@@ -20,6 +20,9 @@ void ImageViewWidget::setImage(const QString &path)
     QImageReader reader(path);
     reader.setAutoTransform(true);
     reader.setDecideFormatFromContent(true);
+    // Disable the allocation limit so very large images can be viewed.
+    // The default 128 MB limit rejects high-resolution photos.
+    reader.setAllocationLimit(0);
     QImage image = reader.read();
 
     if (!image.isNull()) {
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index fd2b7a6..c6fe438 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -258,6 +258,12 @@ void MainWindow::showPreview(const QModelIndex &index)
 
     QImageReader reader(path);
     reader.setAutoTransform(true);
+    // Scale during decoding for the preview to avoid the 128 MB allocation limit
+    QSize fullSize = reader.size();
+    if (fullSize.isValid()) {
+        QSize target = fullSize.scaled(m_previewLabel->size(), Qt::KeepAspectRatio);
+        reader.setScaledSize(target);
+    }
     QImage image = reader.read();
 
     m_previewLabel->setPixmap(
diff --git a/src/thumbnailworker.cpp b/src/thumbnailworker.cpp
index 9b094ba..5a209ab 100644
--- a/src/thumbnailworker.cpp
+++ b/src/thumbnailworker.cpp
@@ -20,6 +20,14 @@ void ThumbnailWorker::run()
     QImageReader reader(m_path);
     reader.setAutoTransform(true);
 
+    // Scale during decoding to avoid hitting the allocation limit
+    // on very large images (Qt 6 defaults to 128 MB).
+    QSize fullSize = reader.size();
+    if (fullSize.isValid()) {
+        QSize target = fullSize.scaled(128, 128, Qt::KeepAspectRatio);
+        reader.setScaledSize(target);
+    }
+
     QImage image = reader.read();
 
     if (*m_cancelFlag)
@@ -28,6 +36,7 @@ void ThumbnailWorker::run()
     if (!image.isNull())
     {
         // Scale to fit within 128x128 keeping aspect ratio
+        // (may already be the right size if setScaledSize succeeded)
         QImage scaled = image.scaled(128, 128,
                                      Qt::KeepAspectRatio,
                                      Qt::SmoothTransformation);