diff --git a/CMakeLists.txt b/CMakeLists.txt
index ba8f1c8..c77dbd8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,8 +7,21 @@ set(CMAKE_AUTOMOC ON)
 include(GNUInstallDirs)
 
 find_package(Qt6 REQUIRED COMPONENTS Widgets LinguistTools)
-find_package(PkgConfig REQUIRED)
-pkg_check_modules(EXIV2 REQUIRED exiv2)
+include(FetchContent)
+set(EXIV2_BUILD_SAMPLES OFF CACHE INTERNAL "")
+set(EXIV2_BUILD_EXIV2_COMMAND OFF CACHE INTERNAL "")
+set(EXIV2_BUILD_UNIT_TESTS OFF CACHE INTERNAL "")
+set(EXIV2_BUILD_DOC OFF CACHE INTERNAL "")
+set(EXIV2_ENABLE_INIH OFF CACHE INTERNAL "")
+FetchContent_Declare(
+    exiv2
+    GIT_REPOSITORY https://github.com/Exiv2/exiv2.git
+    GIT_TAG v0.28.8
+)
+FetchContent_MakeAvailable(exiv2)
+
+# Exiv2 0.28.8 generates this header in the build root but doesn't add it to include paths
+target_include_directories(exiv2lib INTERFACE $<BUILD_INTERFACE:${CMAKE_BINARY_DIR}>)
 
 qt_add_executable(SagoImageBrowser
     src/main.cpp
@@ -38,12 +51,11 @@ qt_add_executable(SagoImageBrowser
 set_source_files_properties(extra/icons/sago_image_browser.svg PROPERTIES QT_RESOURCE_ALIAS sago_image_browser.svg)
 qt_add_resources(SagoImageBrowser "icons" PREFIX "/icons" FILES extra/icons/sago_image_browser.svg)
 
-target_include_directories(SagoImageBrowser PRIVATE ${EXIV2_INCLUDE_DIRS})
-target_link_libraries(SagoImageBrowser PRIVATE Qt6::Widgets ${EXIV2_LIBRARIES})
+target_link_libraries(SagoImageBrowser PRIVATE Qt6::Widgets exiv2lib)
 
 add_executable(test_exifreader test/test_exifreader.cpp src/exifreader.cpp)
-target_include_directories(test_exifreader PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src ${EXIV2_INCLUDE_DIRS})
-target_link_libraries(test_exifreader PRIVATE Qt6::Widgets ${EXIV2_LIBRARIES})
+target_include_directories(test_exifreader PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/src)
+target_link_libraries(test_exifreader PRIVATE Qt6::Widgets exiv2lib)
 
 qt_add_translations(SagoImageBrowser
     TS_FILES translations/da.ts
diff --git a/extra/docker/Dockerfile b/extra/docker/Dockerfile
index d3579f3..9c24b31 100644
--- a/extra/docker/Dockerfile
+++ b/extra/docker/Dockerfile
@@ -7,6 +7,8 @@ RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
 RUN apt-get update && apt-get install --no-install-recommends -y \
     build-essential \
     cmake \
+    git \
+    ca-certificates \
     pkg-config \
     qt6-base-dev \
     qt6-tools-dev \
@@ -14,7 +16,9 @@ RUN apt-get update && apt-get install --no-install-recommends -y \
     libqt6core6 \
     libqt6gui6 \
     libqt6widgets6 \
-    libexiv2-dev \
+    zlib1g-dev \
+    libexpat1-dev \
+    libbrotli-dev \
     && rm -rf /var/lib/apt/lists/*
 
 RUN mkdir -p /staging/sago_image_browser
diff --git a/src/exifreader.cpp b/src/exifreader.cpp
index 0ee3e61..48ab6d6 100644
--- a/src/exifreader.cpp
+++ b/src/exifreader.cpp
@@ -34,6 +34,39 @@ static void addField(QList<QPair<QString, QString>> &result, const char *label, 
         result.append({QString::fromLatin1(label), value});
 }
 
+// EXIF orientation values run 1-8 and may encode mirroring. A 90-degree
+// rotation maps each value to another; the tables below cover all eight so
+// mirrored images stay correct. Unknown values are treated as 1 (normal).
+static int orientationRotatedClockwise(int orientation)
+{
+    switch (orientation) {
+    case 1: return 6;
+    case 2: return 7;
+    case 3: return 8;
+    case 4: return 5;
+    case 5: return 2;
+    case 6: return 3;
+    case 7: return 4;
+    case 8: return 1;
+    default: return 6;
+    }
+}
+
+static int orientationRotatedCounterClockwise(int orientation)
+{
+    switch (orientation) {
+    case 1: return 8;
+    case 2: return 5;
+    case 3: return 6;
+    case 4: return 7;
+    case 5: return 4;
+    case 6: return 1;
+    case 7: return 2;
+    case 8: return 3;
+    default: return 8;
+    }
+}
+
 bool ExifData::isEmpty() const
 {
     return captionAbstract.isEmpty() && description.isEmpty()
@@ -172,3 +205,27 @@ bool ExifReader::saveCaption(const QByteArray &path,
         return false;
     }
 }
+
+bool ExifReader::rotate(const QByteArray &path, bool clockwise)
+{
+    try {
+        std::unique_ptr<Exiv2::Image> image =
+            Exiv2::ImageFactory::open(path.toStdString());
+        image->readMetadata();
+        Exiv2::ExifData &exif = image->exifData();
+
+        int current = 1; // EXIF default when the tag is absent
+        auto it = exif.findKey(Exiv2::ExifKey("Exif.Image.Orientation"));
+        if (it != exif.end())
+            current = static_cast<int>(it->toInt64());
+
+        const int updated = clockwise ? orientationRotatedClockwise(current)
+                                      : orientationRotatedCounterClockwise(current);
+        exif["Exif.Image.Orientation"] = static_cast<uint16_t>(updated);
+
+        image->writeMetadata();
+        return true;
+    } catch (const Exiv2::Error &) {
+        return false;
+    }
+}
diff --git a/src/exifreader.h b/src/exifreader.h
index c6b1d29..bdd6632 100644
--- a/src/exifreader.h
+++ b/src/exifreader.h
@@ -34,4 +34,9 @@ ExifData read(const QByteArray &path);
 bool saveCaption(const QByteArray &path,
                  const QString    &caption,
                  const ExifData   &oldData);
+
+// Rotate the image 90 degrees by updating the Exif.Image.Orientation tag only
+// (lossless — pixel data is left untouched). clockwise=true rotates right.
+// Returns true on success.
+bool rotate(const QByteArray &path, bool clockwise);
 } // namespace ExifReader
diff --git a/src/imagemodel.cpp b/src/imagemodel.cpp
index 340c6f6..e15e0f5 100644
--- a/src/imagemodel.cpp
+++ b/src/imagemodel.cpp
@@ -226,6 +226,23 @@ void ImageModel::requestThumbnails(int firstRow, int lastRow)
             queueRow(row);
 }
 
+void ImageModel::refreshThumbnail(const QModelIndex &index)
+{
+    if (!index.isValid())
+        return;
+
+    const int row = index.row();
+    if (row < 0 || row >= m_items.size() || m_items[row].isFolder)
+        return;
+
+    // The on-disk thumbnail cache is keyed by source mtime, so it invalidates
+    // itself once the file is rewritten. Drop the in-memory copy and re-decode.
+    m_items[row].thumbnail = m_placeholder;
+    m_items[row].loaded = false;
+    emit dataChanged(index, index, {Qt::DecorationRole});
+    queueRow(row);
+}
+
 void ImageModel::queueRow(int row)
 {
     if (m_pendingRows.contains(row))
diff --git a/src/imagemodel.h b/src/imagemodel.h
index e64708d..35b200c 100644
--- a/src/imagemodel.h
+++ b/src/imagemodel.h
@@ -31,6 +31,8 @@ public:
     QByteArray currentDirectory() const;
 
     void requestThumbnails(int firstRow, int lastRow);
+    // Discard the cached thumbnail for a row and re-decode it from disk.
+    void refreshThumbnail(const QModelIndex &index);
     void setCacheMaxSize(int n);
     void setThumbnailSize(ThumbnailCache::Size size);
 
diff --git a/src/imageviewwidget.cpp b/src/imageviewwidget.cpp
index 837873f..ed2cd7c 100644
--- a/src/imageviewwidget.cpp
+++ b/src/imageviewwidget.cpp
@@ -171,6 +171,11 @@ void ImageViewWidget::clearCache()
     m_neighborPaths.clear();
 }
 
+void ImageViewWidget::invalidateCache(const QByteArray &path)
+{
+    m_cache.remove(path);
+}
+
 void ImageViewWidget::setBackgroundColor(const QString &color)
 {
     m_backgroundColor = color;
diff --git a/src/imageviewwidget.h b/src/imageviewwidget.h
index be1091a..78f13a1 100644
--- a/src/imageviewwidget.h
+++ b/src/imageviewwidget.h
@@ -45,6 +45,8 @@ public:
     void prefetchImage(const QByteArray &path);
     void setNeighborPaths(const QList<QByteArray> &paths);
     void clearCache();
+    // Drop any cached pixmap for path so it is re-decoded from disk next time.
+    void invalidateCache(const QByteArray &path);
 
     void setExifData(const ExifData &data);
     void toggleExifOverlay();
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 092e327..bfd1d7e 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -640,6 +640,9 @@ void MainWindow::showImageContextMenu(const QPoint &pos)
     QAction *copyFilenameAction = menu.addAction(tr("Copy filename"));
     QAction *copyFullPathAction = menu.addAction(tr("Copy full path"));
     menu.addSeparator();
+    QAction *rotateLeftAction = menu.addAction(tr("Rotate Left"));
+    QAction *rotateRightAction = menu.addAction(tr("Rotate Right"));
+    menu.addSeparator();
     QAction *editDescriptionAction = menu.addAction(tr("Edit description"));
     QAction *moveToTrashAction = menu.addAction(tr("Move to trash"));
     moveToTrashAction->setShortcut(
@@ -650,6 +653,10 @@ void MainWindow::showImageContextMenu(const QPoint &pos)
         QGuiApplication::clipboard()->setText(filenameFromPath(path));
     } else if (chosen == copyFullPathAction) {
         QGuiApplication::clipboard()->setText(displayPath(path));
+    } else if (chosen == rotateLeftAction) {
+        rotateImage(index, false);
+    } else if (chosen == rotateRightAction) {
+        rotateImage(index, true);
     } else if (chosen == editDescriptionAction) {
         onEditCaption();
     } else if (chosen == moveToTrashAction) {
@@ -657,6 +664,38 @@ void MainWindow::showImageContextMenu(const QPoint &pos)
     }
 }
 
+void MainWindow::rotateImage(const QModelIndex &index, bool clockwise)
+{
+    if (!index.isValid() || m_imageModel->isFolder(index))
+        return;
+
+    const QByteArray path = m_imageModel->filePath(index);
+
+    if (::access(path.constData(), W_OK) != 0) {
+        QMessageBox::warning(this, tr("Cannot Rotate Image"),
+            tr("The file is write-protected and cannot be rotated.\n\n%1")
+                .arg(displayPath(path)));
+        return;
+    }
+
+    if (!ExifReader::rotate(path, clockwise)) {
+        QMessageBox::warning(this, tr("Cannot Rotate Image"),
+            tr("The image orientation could not be changed. The format may not "
+               "support EXIF orientation.\n\n%1")
+                .arg(displayPath(path)));
+        return;
+    }
+
+    m_imageModel->refreshThumbnail(index);
+    showPreview(index);
+
+    if (m_imageView->currentPath() == path) {
+        m_imageView->invalidateCache(path);
+        m_imageView->setImage(path);
+        m_imageView->setExifData(ExifReader::read(path));
+    }
+}
+
 void MainWindow::moveImageToTrash(const QByteArray &path)
 {
     if (path.isEmpty())
diff --git a/src/mainwindow.h b/src/mainwindow.h
index 26a6c57..e4dde9e 100644
--- a/src/mainwindow.h
+++ b/src/mainwindow.h
@@ -50,6 +50,7 @@ private:
     void showImageContextMenu(const QPoint &pos);
     void moveImageToTrash(const QByteArray &path);
     void moveCurrentImageToTrash();
+    void rotateImage(const QModelIndex &index, bool clockwise);
     void onPathEntered();
     void updatePathField(const QByteArray &path);
     QList<QByteArray> computeNeighborPaths(const QModelIndex &index) const;