diff --git a/src/corelib/kernel/qmetatype.cpp b/src/corelib/kernel/qmetatype.cpp
index a1baf28f10..0021c0ced2 100644
--- a/src/corelib/kernel/qmetatype.cpp
+++ b/src/corelib/kernel/qmetatype.cpp
@@ -1318,7 +1318,7 @@ public:
     template<typename T>
     void delegate(const T *where) { DestroyerImpl<T>::Destroy(m_type, const_cast<T*>(where)); }
     void delegate(const void *) {}
-    void delegate(const QMetaTypeSwitcher::UnknownType *where) { customTypeDestroyer(m_type, (void*)where); }
+    void delegate(const QMetaTypeSwitcher::NotBuiltinType *where) { customTypeDestroyer(m_type, (void*)where); }
 
 private:
     static void customTypeDestroyer(const int type, void *where)
@@ -1380,7 +1380,7 @@ public:
     template<typename T>
     void *delegate(const T *copy) { return ConstructorImpl<T>::Construct(m_type, m_where, copy); }
     void *delegate(const void *) { return m_where; }
-    void *delegate(const QMetaTypeSwitcher::UnknownType *copy) { return customTypeConstructor(m_type, m_where, copy); }
+    void *delegate(const QMetaTypeSwitcher::NotBuiltinType *copy) { return customTypeConstructor(m_type, m_where, copy); }
 
 private:
     static void *customTypeConstructor(const int type, void *where, const void *copy)
@@ -1468,7 +1468,7 @@ public:
     template<typename T>
     void delegate(const T *where) { DestructorImpl<T>::Destruct(m_type, const_cast<T*>(where)); }
     void delegate(const void *) {}
-    void delegate(const QMetaTypeSwitcher::UnknownType *where) { customTypeDestructor(m_type, (void*)where); }
+    void delegate(const QMetaTypeSwitcher::NotBuiltinType *where) { customTypeDestructor(m_type, (void*)where); }
 
 private:
     static void customTypeDestructor(const int type, void *where)
@@ -1536,7 +1536,7 @@ public:
 
     template<typename T>
     int delegate(const T*) { return SizeOfImpl<T>::Size(m_type); }
-    int delegate(const QMetaTypeSwitcher::UnknownType*) { return customTypeSizeOf(m_type); }
+    int delegate(const QMetaTypeSwitcher::NotBuiltinType*) { return customTypeSizeOf(m_type); }
 private:
     static int customTypeSizeOf(const int type)
     {
@@ -1606,7 +1606,7 @@ public:
     template<typename T>
     quint32 delegate(const T*) { return FlagsImpl<T>::Flags(m_type); }
     quint32 delegate(const void*) { return 0; }
-    quint32 delegate(const QMetaTypeSwitcher::UnknownType*) { return customTypeFlags(m_type); }
+    quint32 delegate(const QMetaTypeSwitcher::NotBuiltinType*) { return customTypeFlags(m_type); }
 private:
     const int m_type;
     static quint32 customTypeFlags(const int type)
@@ -1793,7 +1793,7 @@ public:
     template<typename T>
     void delegate(const T*) { TypeInfoImpl<T>(m_type, info); }
     void delegate(const void*) {}
-    void delegate(const QMetaTypeSwitcher::UnknownType*) { customTypeInfo(m_type); }
+    void delegate(const QMetaTypeSwitcher::NotBuiltinType*) { customTypeInfo(m_type); }
 private:
     void customTypeInfo(const uint type)
     {
diff --git a/src/corelib/kernel/qmetatypeswitcher_p.h b/src/corelib/kernel/qmetatypeswitcher_p.h
index c1cccfca63..05db2cb4c7 100644
--- a/src/corelib/kernel/qmetatypeswitcher_p.h
+++ b/src/corelib/kernel/qmetatypeswitcher_p.h
@@ -60,7 +60,7 @@ QT_BEGIN_NAMESPACE
 class QMetaTypeSwitcher {
 public:
 
-    typedef void *UnknownType;
+    typedef void *NotBuiltinType;
     template<class ReturnType, class DelegateObject>
     static ReturnType switcher(DelegateObject &logic, int type, const void *data);
 };
@@ -91,7 +91,7 @@ ReturnType QMetaTypeSwitcher::switcher(DelegateObject &logic, int type, const vo
     QT_FOR_EACH_STATIC_WIDGETS_CLASS(QT_METATYPE_SWICHER_CASE_QCLASS)
 
     default:
-        return logic.delegate(static_cast<const UnknownType *>(data));
+        return logic.delegate(static_cast<const NotBuiltinType *>(data));
     }
 }
 
diff --git a/src/corelib/kernel/qvariant_p.h b/src/corelib/kernel/qvariant_p.h
index c428d81bb4..708a427860 100644
--- a/src/corelib/kernel/qvariant_p.h
+++ b/src/corelib/kernel/qvariant_p.h
@@ -345,7 +345,7 @@ public:
         FilteredConstructor<T>(*this);
     }
 
-    void delegate(const QMetaTypeSwitcher::UnknownType*)
+    void delegate(const QMetaTypeSwitcher::NotBuiltinType*)
     {
         qWarning("Trying to construct an instance of an invalid type, type id: %i", m_x->type);
         m_x->type = QVariant::Invalid;
@@ -395,7 +395,7 @@ public:
         FilteredDestructor<T> cleaner(m_d);
     }
 
-    void delegate(const QMetaTypeSwitcher::UnknownType*)
+    void delegate(const QMetaTypeSwitcher::NotBuiltinType*)
     {
         qWarning("Trying to destruct an instance of an invalid type, type id: %i", m_d->type);
     }
@@ -441,7 +441,7 @@ public:
         Filtered<T> streamIt(m_debugStream, m_d);
     }
 
-    void delegate(const QMetaTypeSwitcher::UnknownType*)
+    void delegate(const QMetaTypeSwitcher::NotBuiltinType*)
     {
         qWarning("Trying to stream an instance of an invalid type, type id: %i", m_d->type);
     }