diff --git a/src/corelib/kernel/qobject_p.h b/src/corelib/kernel/qobject_p.h
index 539818ac1d..c119fdfe7e 100644
--- a/src/corelib/kernel/qobject_p.h
+++ b/src/corelib/kernel/qobject_p.h
@@ -467,10 +467,35 @@ inline void QObjectPrivate::disconnectNotify(const QMetaMethod &signal)
 }
 
 namespace QtPrivate {
-template<typename Func, typename Args, typename R> class QPrivateSlotObject : public QSlotObjectBase
+
+template <typename Func>
+struct FunctionStorageByValue
+{
+    Func f;
+    Func &func() noexcept { return f; }
+};
+
+template <typename Func>
+struct FunctionStorageEmptyBaseClassOptimization : Func
+{
+    Func &func() noexcept { return *this; }
+    using Func::Func;
+};
+
+template <typename Func>
+using FunctionStorage = typename std::conditional_t<
+        std::conjunction_v<
+            std::is_empty<Func>,
+            std::negation<std::is_final<Func>>
+        >,
+        FunctionStorageEmptyBaseClassOptimization<Func>,
+        FunctionStorageByValue<Func>
+    >;
+
+template<typename Func, typename Args, typename R>
+class QPrivateSlotObject : public QSlotObjectBase, private FunctionStorage<Func>
 {
     typedef QtPrivate::FunctionPointer<Func> FuncType;
-    Func function;
     static void impl(int which, QSlotObjectBase *this_, QObject *r, void **a, bool *ret)
     {
         switch (which) {
@@ -478,17 +503,17 @@ template<typename Func, typename Args, typename R> class QPrivateSlotObject : pu
                 delete static_cast<QPrivateSlotObject*>(this_);
                 break;
             case Call:
-                FuncType::template call<Args, R>(static_cast<QPrivateSlotObject*>(this_)->function,
+                FuncType::template call<Args, R>(static_cast<QPrivateSlotObject*>(this_)->func(),
                                                  static_cast<typename FuncType::Object *>(QObjectPrivate::get(r)), a);
                 break;
             case Compare:
-                *ret = *reinterpret_cast<Func *>(a) == static_cast<QPrivateSlotObject*>(this_)->function;
+                *ret = *reinterpret_cast<Func *>(a) == static_cast<QPrivateSlotObject*>(this_)->func();
                 break;
             case NumOperations: ;
         }
     }
 public:
-    explicit QPrivateSlotObject(Func f) : QSlotObjectBase(&impl), function(f) {}
+    explicit QPrivateSlotObject(Func f) : QSlotObjectBase(&impl), FunctionStorage<Func>{std::move(f)} {}
 };
 } //namespace QtPrivate
 
diff --git a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
index 3d52478299..599f690ab2 100644
--- a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
+++ b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp
@@ -5221,7 +5221,7 @@ namespace ManyArgumentNamespace {
         }
     };
 
-    struct Funct6 {
+    struct Funct6 final {
         void operator()(const QString &a, const QString &b, const QString &c, const QString&d, const QString&e, const QString&f) {
             MANYARGUMENT_COMPARE(a); MANYARGUMENT_COMPARE(b); MANYARGUMENT_COMPARE(c);
             MANYARGUMENT_COMPARE(d); MANYARGUMENT_COMPARE(e); MANYARGUMENT_COMPARE(f);