diff --git a/src/core/tests/test_layouter.cpp b/src/core/tests/test_layouter.cpp
index e249bce3..bce182ff 100644
--- a/src/core/tests/test_layouter.cpp
+++ b/src/core/tests/test_layouter.cpp
@@ -72,10 +72,10 @@ private Q_SLOTS:
         }
     }
 
-    static void assertRegionContainsStates(State *region, const QList<State *> states)
+    static void assertRegionContainsStates(State *region, const QList<State *> &states)
     {
         const QRectF rect = region->boundingRect();
-        foreach (State *item, states) {
+        for (const State *item : states) {
             QVERIFY(rect.contains(item->boundingRect()));
         }
     }
diff --git a/src/core/util/objecthelper.cpp b/src/core/util/objecthelper.cpp
index ce74b9bc..4dc925e1 100644
--- a/src/core/util/objecthelper.cpp
+++ b/src/core/util/objecthelper.cpp
@@ -41,7 +41,7 @@ QString ObjectHelper::addressToString(const void *p)
 QString ObjectHelper::className(const QObject *object, ObjectHelper::DisplayOption option)
 {
     QString className = QString::fromLatin1(object->metaObject()->className());
-    return option == StripNameSpace ? stripNameSpace(className) : className;
+    return option == StripNameSpace ? stripNameSpace(className) : std::move(className);
 }
 
 QString ObjectHelper::displayString(const QObject *object, DisplayOption option)
diff --git a/src/core/util/objecthelper.h b/src/core/util/objecthelper.h
index abbd1fff..8a34f7fb 100644
--- a/src/core/util/objecthelper.h
+++ b/src/core/util/objecthelper.h
@@ -71,10 +71,10 @@ KDSME_CORE_EXPORT int depth(const QObject *root, const QObject *object);
  * Returns a list that only contains item of type @p FilterType
  */
 template<class FilterType, class ItemType>
-QList<FilterType> copy_if_type(const QList<ItemType> list)
+QList<FilterType> copy_if_type(const QList<ItemType> &list)
 {
     QList<FilterType> filteredList;
-    Q_FOREACH (const ItemType object, list) {
+    for (const ItemType &object : list) {
         if (FilterType filterObject = qobject_cast<FilterType>(object))
             filteredList << filterObject;
     }
diff --git a/src/view/widgets/statemachineview.cpp b/src/view/widgets/statemachineview.cpp
index a27a0823..553809e9 100644
--- a/src/view/widgets/statemachineview.cpp
+++ b/src/view/widgets/statemachineview.cpp
@@ -241,7 +241,7 @@ void StateMachineView::setThemeName(const QString &themeName)
         }
     }
 
-    d->m_themeName = selectedThemeName;
+    d->m_themeName = std::move(selectedThemeName);
     emit themeNameChanged(d->m_themeName);
 }