diff --git a/src/models/appsmodel.cpp b/src/models/appsmodel.cpp
index f2086062..b172abe8 100644
--- a/src/models/appsmodel.cpp
+++ b/src/models/appsmodel.cpp
@@ -113,12 +113,17 @@ void AppsModel::setSourceModel(QAbstractItemModel *model)
     rebuildRows();
 }
 
-QModelIndex AppsModel::indexFromDesktopId(const QString &desktopId) const
+QModelIndex AppsModel::indexFromAppId(const QString &appId) const
 {
     if (rowCount() == 0)
         return {};
+    return match(index(0, 0), DesktopIdRole, appId, 1, Qt::MatchExactly).value(0);
+}
+
+QModelIndex AppsModel::indexFromDesktopId(const QString &desktopId) const
+{
     for (int i = 0; i < rowCount(); ++i) {
-        if (AppsModel::normalizedDesktopId(desktopId) == AppsModel::normalizedDesktopId(data(index(i, 0), DesktopIdRole).toString()))
+        if (desktopId == normalizedDesktopId(data(index(i, 0), DesktopIdRole).toString()))
             return index(i, 0);
     }
     return {};
diff --git a/src/models/appsmodel.h b/src/models/appsmodel.h
index aa44e377..2a85053f 100644
--- a/src/models/appsmodel.h
+++ b/src/models/appsmodel.h
@@ -59,10 +59,13 @@ class AppsModel : public QAbstractListModel
     }
 
     void setSourceModel(QAbstractItemModel *sourceModel);
+    // Raw app IDs come from dde-shell; desktop file IDs include one extra .desktop suffix.
+    QModelIndex indexFromAppId(const QString &appId) const;
     QModelIndex indexFromDesktopId(const QString &desktopId) const;
     bool ready() const;
     QVariantMap ddeCategories() const;
 
+    // Convert a raw app ID to a desktop file ID, even when the app ID ends in .desktop.
     static QString normalizedDesktopId(const QString &sourceId);
 
     int rowCount(const QModelIndex &parent = QModelIndex()) const override;
diff --git a/src/models/itemarrangementproxymodel.cpp b/src/models/itemarrangementproxymodel.cpp
index f56807af..74345eee 100644
--- a/src/models/itemarrangementproxymodel.cpp
+++ b/src/models/itemarrangementproxymodel.cpp
@@ -163,7 +163,7 @@ void ItemArrangementProxyModel::commitDndOperation(const QString &dragId, const
             ItemsPage * dstFolder = createFolder(dstFolderId);
             qCDebug(logModels) << "Appending items to new folder page:" << dropId << dragId;
             dstFolder->appendPage({normDropId, normDragId});
-            const QModelIndex dropItem = AppsModel::instance().indexFromDesktopId(dropId);
+            const QModelIndex dropItem = AppsModel::instance().indexFromAppId(dropId);
             if (dropItem.isValid()) {
                 const int dropCategory = dropItem.data(AppsModel::DDECategoryRole).toInt();
                 QString folderName = "internal/category/" + QString::number(dropCategory);
diff --git a/tests/searchfilterproxymodeltest.cpp b/tests/searchfilterproxymodeltest.cpp
index 06fa5695..20c3f30c 100644
--- a/tests/searchfilterproxymodeltest.cpp
+++ b/tests/searchfilterproxymodeltest.cpp
@@ -382,16 +382,18 @@ void TestSearchFilterProxyModel::testSharedModelAdapter()
     QCOMPARE(appsModel.indexFromDesktopId("org.test.hidden.desktop").data(AppsModel::DesktopIdRole).toString(),
              QStringLiteral("org.test.hidden"));
 
-    auto suffixedItem = createTestAppItem("org.test.suffixed", "Suffixed", "Suffixed");
+    auto suffixedItem = createTestAppItem("org.test.suffixed.desktop", "Suffixed", "Suffixed");
     m_sourceModel.appendRow(suffixedItem);
     QCOMPARE(rowsInsertedSpy.count(), 2);
-    const QModelIndex suffixedIndex = appsModel.indexFromDesktopId("org.test.suffixed");
+    const QModelIndex suffixedIndex = appsModel.indexFromAppId("org.test.suffixed.desktop");
     QCOMPARE(suffixedIndex.data(AppsModel::DesktopIdRole).toString(),
-             QStringLiteral("org.test.suffixed"));
+             QStringLiteral("org.test.suffixed.desktop"));
+    QCOMPARE(AppsModel::normalizedDesktopId("org.test.suffixed.desktop"),
+             QStringLiteral("org.test.suffixed.desktop.desktop"));
 
     QSignalSpy dataChangedSpy(&appsModel, &QAbstractItemModel::dataChanged);
     suffixedItem->setData(QStringLiteral("Renamed"), SourceNameRole);
-    QCOMPARE(appsModel.indexFromDesktopId("org.test.suffixed").data(Qt::DisplayRole).toString(),
+    QCOMPARE(appsModel.indexFromDesktopId("org.test.suffixed.desktop.desktop").data(Qt::DisplayRole).toString(),
              QStringLiteral("Renamed"));
     QVERIFY(!dataChangedSpy.isEmpty());
     const auto changedRoles = dataChangedSpy.constLast().at(2).value<QList<int>>();