diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h
index 5ce3f26b53..80c1f21c0d 100644
--- a/src/corelib/kernel/qmetatype.h
+++ b/src/corelib/kernel/qmetatype.h
@@ -1789,16 +1789,32 @@ struct QMetaTypeId< DOUBLE_ARG_TEMPLATE<T, U> > \
     } \
 };
 
+namespace QtPrivate {
+
+template<typename T, bool /* isSharedPointerToQObjectDerived */ = false>
+struct SharedPointerMetaTypeIdHelper
+{
+    enum {
+        Defined = 0
+    };
+    static int qt_metatype_id()
+    {
+        return -1;
+    }
+};
+
+}
+
 #define Q_DECLARE_SMART_POINTER_METATYPE(SMART_POINTER) \
-template <typename T> \
-struct QMetaTypeId< SMART_POINTER<T> > \
+QT_BEGIN_NAMESPACE \
+namespace QtPrivate { \
+template<typename T> \
+struct SharedPointerMetaTypeIdHelper<SMART_POINTER<T>, true> \
 { \
     enum { \
-        Defined = QtPrivate::IsPointerToTypeDerivedFromQObject<T*>::Value \
+        Defined = 1 \
     }; \
-    static \
-    typename QtPrivate::QEnableIf<QtPrivate::IsPointerToTypeDerivedFromQObject<T*>::Value, int>::Type \
-    qt_metatype_id() \
+    static int qt_metatype_id() \
     { \
         static QBasicAtomicInt metatype_id = Q_BASIC_ATOMIC_INITIALIZER(0); \
         if (const int id = metatype_id.loadAcquire()) \
@@ -1814,7 +1830,15 @@ struct QMetaTypeId< SMART_POINTER<T> > \
         metatype_id.storeRelease(newId); \
         return newId; \
     } \
+}; \
+} \
+template <typename T> \
+struct QMetaTypeId< SMART_POINTER<T> > \
+    : QtPrivate::SharedPointerMetaTypeIdHelper< SMART_POINTER<T>, \
+                                                QtPrivate::IsPointerToTypeDerivedFromQObject<T*>::Value> \
+{ \
 };\
+QT_END_NAMESPACE \
 
 #define QT_FOR_EACH_AUTOMATIC_TEMPLATE_SMART_POINTER(F) \
     F(QSharedPointer) \
@@ -1846,8 +1870,12 @@ Q_DECLARE_METATYPE_TEMPLATE_2ARG(std::map)
 #define Q_DECLARE_METATYPE_TEMPLATE_SMART_POINTER_ITER(TEMPLATENAME) \
     Q_DECLARE_SMART_POINTER_METATYPE(TEMPLATENAME)
 
+QT_END_NAMESPACE
+
 QT_FOR_EACH_AUTOMATIC_TEMPLATE_SMART_POINTER(Q_DECLARE_METATYPE_TEMPLATE_SMART_POINTER_ITER)
 
+QT_BEGIN_NAMESPACE
+
 #undef Q_DECLARE_METATYPE_TEMPLATE_SMART_POINTER_ITER
 
 inline QMetaType::QMetaType(const ExtensionFlag extensionFlags, const QMetaTypeInterface *info,
diff --git a/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp b/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp
index 6baf6c4310..0b50bc7576 100644
--- a/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp
+++ b/tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp
@@ -2259,6 +2259,28 @@ struct Converter
   }
 };
 
+namespace MyNS {
+
+template<typename T>
+class SmartPointer
+{
+    T* pointer;
+public:
+    typedef T element_type;
+    explicit SmartPointer(T *t = 0)
+      : pointer(t)
+    {
+    }
+
+    T* operator->() const { return pointer; }
+};
+
+}
+
+Q_DECLARE_SMART_POINTER_METATYPE(MyNS::SmartPointer)
+
+Q_DECLARE_METATYPE(MyNS::SmartPointer<int>)
+
 void tst_QVariant::qvariant_cast_QObject_wrapper()
 {
     QMetaType::registerConverter<QObjectWrapper, QObject*>(&QObjectWrapper::getObject);
@@ -2270,6 +2292,10 @@ void tst_QVariant::qvariant_cast_QObject_wrapper()
     v.convert(qMetaTypeId<QObject*>());
     QCOMPARE(v.value<QObject*>(), object);
 
+    // Compile tests:
+    qRegisterMetaType<MyNS::SmartPointer<int> >();
+    // Not declared as a metatype:
+    qRegisterMetaType<MyNS::SmartPointer<double> >("MyNS::SmartPointer<double>");
 }
 
 void tst_QVariant::convertToQUint8() const