diff --git a/src/plugins/qmldesigner/designercore/projectstorage/projectstorageupdater.h b/src/plugins/qmldesigner/designercore/projectstorage/projectstorageupdater.h
index 22778ac932a..519d11a920a 100644
--- a/src/plugins/qmldesigner/designercore/projectstorage/projectstorageupdater.h
+++ b/src/plugins/qmldesigner/designercore/projectstorage/projectstorageupdater.h
@@ -32,7 +32,7 @@ class ProjectStorage;
 class QmlDocumentParserInterface;
 class QmlTypesParserInterface;
 
-class ProjectStorageUpdater : public ProjectStoragePathWatcherNotifierInterface
+class ProjectStorageUpdater final : public ProjectStoragePathWatcherNotifierInterface
 {
 public:
     using PathCache = SourcePathCache<ProjectStorage<Sqlite::Database>, NonLockingMutex>;
diff --git a/src/plugins/qmldesigner/designercore/projectstorage/qmldocumentparser.h b/src/plugins/qmldesigner/designercore/projectstorage/qmldocumentparser.h
index 2896d54ebe7..96f28a4585f 100644
--- a/src/plugins/qmldesigner/designercore/projectstorage/qmldocumentparser.h
+++ b/src/plugins/qmldesigner/designercore/projectstorage/qmldocumentparser.h
@@ -12,7 +12,7 @@ namespace QmlDesigner {
 template<typename ProjectStorage, typename Mutex>
 class SourcePathCache;
 
-class QmlDocumentParser : public QmlDocumentParserInterface
+class QmlDocumentParser final : public QmlDocumentParserInterface
 {
 public:
     using ProjectStorage = QmlDesigner::ProjectStorage<Sqlite::Database>;
diff --git a/src/plugins/qmldesigner/designercore/projectstorage/qmltypesparser.h b/src/plugins/qmldesigner/designercore/projectstorage/qmltypesparser.h
index c1d9a3a0d45..6fcf82a2bb2 100644
--- a/src/plugins/qmldesigner/designercore/projectstorage/qmltypesparser.h
+++ b/src/plugins/qmldesigner/designercore/projectstorage/qmltypesparser.h
@@ -18,7 +18,7 @@ class ProjectStorage;
 template<typename ProjectStorage, typename Mutex>
 class SourcePathCache;
 
-class QmlTypesParser : public QmlTypesParserInterface
+class QmlTypesParser final : public QmlTypesParserInterface
 {
 public:
     using ProjectStorage = QmlDesigner::ProjectStorage<Sqlite::Database>;