diff --git a/tools/chatgui/tests/test_dm_deletion.cpp b/tools/chatgui/tests/test_dm_deletion.cpp
index 29d3bb28..5d95b391 100644
--- a/tools/chatgui/tests/test_dm_deletion.cpp
+++ b/tools/chatgui/tests/test_dm_deletion.cpp
@@ -62,6 +62,47 @@ class DmDeletionTest : public QObject {
 private slots:
     void initTestCase() { debug_config_init(); gui_bridge_init(); }
 
+    void mediaPreviews() {
+        QTemporaryDir directory; QVERIFY(directory.isValid()); debug_set_category_level(DEBUG_CATEGORY_MEDIA, DEBUG_LEVEL_DEBUG);
+        const QString picture = directory.filePath("picture.png"); QImage pixels(1200, 800, QImage::Format_ARGB32);
+        pixels.fill(QColor(30, 150, 70, 90)); QVERIFY(pixels.save(picture, "PNG"));
+        QFile fixture(QFINDTESTDATA("data/preview_video.b64")); QVERIFY(fixture.open(QIODevice::ReadOnly));
+        QFile video(directory.filePath("video.mp4")); QVERIFY(video.open(QIODevice::WriteOnly));
+        QByteArray mp4 = QByteArray::fromBase64(fixture.readAll()); QCOMPARE(video.write(mp4), mp4.size()); video.close();
+        DbManager db; db.setDbPath(directory.path());
+        auto seed = [&](MessageList& history, int count) {
+            auto* view = history.findChild<ChatView*>();
+            auto* model = qobject_cast<QStandardItemModel*>(view->model());
+            for (int row = 0; row < count; ++row) {
+                auto* item = new QStandardItem; item->setData(row + 1, MsgIdRole); item->setData("Alice", MsgAuthorRole);
+                item->setData("12:34", MsgTimeRole); item->setData(row % 2 ? "video/mp4" : "image/png", MsgContentTypeRole);
+                item->setData(row % 2 ? video.fileName() : picture, MsgVoiceFileRole); item->setData(2, MsgFileDownloadStateRole);
+                item->setData(1200, MsgImageWidthRole); item->setData(800, MsgImageHeightRole); item->setData(1000, MsgFileSizeRole);
+                model->appendRow(item);
+            }
+            history.resize(640, 480); history.show(); view->scrollToTop(); return model;
+        };
+        const QString cache = directory.filePath("media_previews/v1"); QHash<QString, QDateTime> dates;
+        {
+            MessageList history(&db); auto* model = seed(history, 24); auto* view = history.findChild<ChatView*>();
+            QTRY_VERIFY_WITH_TIMEOUT(!model->item(0)->data(MsgImagePreviewRole).value<QImage>().isNull(), 5000);
+            QTRY_VERIFY_WITH_TIMEOUT(!model->item(1)->data(MsgImagePreviewRole).value<QImage>().isNull(), 5000);
+            QCOMPARE(QDir(cache).entryList({"*.preview"}, QDir::Files).size(), 2);
+            view->scrollToBottom();
+            QTRY_VERIFY_WITH_TIMEOUT(!model->item(23)->data(MsgImagePreviewRole).value<QImage>().isNull(), 5000);
+            QVERIFY(!model->item(0)->data(MsgImagePreviewRole).isValid());
+            for (const auto& file : QDir(cache).entryInfoList({"*.preview"}, QDir::Files)) dates[file.fileName()] = file.lastModified();
+        }
+        QCoreApplication::sendPostedEvents(nullptr, QEvent::DeferredDelete);
+        {
+            MessageList reopened(&db); auto* model = seed(reopened, 2);
+            QTRY_VERIFY_WITH_TIMEOUT(!model->item(0)->data(MsgImagePreviewRole).value<QImage>().isNull(), 5000);
+            QTRY_VERIFY_WITH_TIMEOUT(!model->item(1)->data(MsgImagePreviewRole).value<QImage>().isNull(), 5000);
+            QCOMPARE(QDir(cache).entryList({"*.preview"}, QDir::Files).size(), 2);
+            for (const auto& file : QDir(cache).entryInfoList({"*.preview"}, QDir::Files)) QCOMPARE(file.lastModified(), dates.value(file.fileName()));
+        }
+    }
+
     void deleteThroughWindowAndCore() {
         QTemporaryDir directory; QVERIFY(directory.isValid());
         directory.setAutoRemove(false);
diff --git a/tools/chatgui/tests/test_media_preview_cache.cpp b/tools/chatgui/tests/test_media_preview_cache.cpp
index 2a2585c8..29d9c177 100644
--- a/tools/chatgui/tests/test_media_preview_cache.cpp
+++ b/tools/chatgui/tests/test_media_preview_cache.cpp
@@ -41,7 +41,7 @@ private slots:
         QTemporaryDir temporary; const QString source = temporary.filePath("original.png"); QVERIFY(image(source, Qt::green));
         Cache cache(temporary.filePath("previews")); auto original = cache.load(source, Kind::Image, Now); QVERIFY(!original.image.isNull());
         QFile record(original.file); QVERIFY(record.open(QIODevice::ReadOnly));
-        QVERIFY(record.setFileTime(QDateTime::fromMSecsSinceEpoch(Now + 20 * LifetimeMs, Qt::UTC), QFileDevice::FileModificationTime)); record.close();
+        QVERIFY(record.setFileTime(QDateTime::fromMSecsSinceEpoch(Now + 20 * LifetimeMs).toUTC(), QFileDevice::FileModificationTime)); record.close();
         const QString unrelated = temporary.filePath("previews/notes.preview"); QFile notes(unrelated); QVERIFY(notes.open(QIODevice::WriteOnly));
         notes.write("unrelated file"); notes.close();
         auto boundary = cache.load(source, Kind::Image, Now + LifetimeMs); QCOMPARE(boundary.created, Now);
@@ -58,7 +58,7 @@ private slots:
         Cache reopened(directory); auto repaired = reopened.load(source, Kind::Image, Now + 1);
         QCOMPARE(int(repaired.origin), int(Origin::Generated)); QVERIFY(repaired.error.isEmpty()); QVERIFY(!repaired.image.isNull());
         QVERIFY(image(source, Qt::blue)); QFile changed(source); QVERIFY(changed.open(QIODevice::ReadOnly));
-        QVERIFY(changed.setFileTime(QDateTime::fromMSecsSinceEpoch(Now + 4000, Qt::UTC), QFileDevice::FileModificationTime)); changed.close();
+        QVERIFY(changed.setFileTime(QDateTime::fromMSecsSinceEpoch(Now + 4000).toUTC(), QFileDevice::FileModificationTime)); changed.close();
         auto blue = reopened.load(source, Kind::Image, Now + 2); QVERIFY(blue.file != red.file);
         QCOMPARE(int(blue.origin), int(Origin::Generated)); QVERIFY(blue.image.pixelColor(30, 30).blue() > 200);
     }