diff --git a/src/gui/kernel/qpixelformat.h b/src/gui/kernel/qpixelformat.h
index 0e5df679f8..87b40577d1 100644
--- a/src/gui/kernel/qpixelformat.h
+++ b/src/gui/kernel/qpixelformat.h
@@ -162,7 +162,7 @@ public:
     Q_DECL_CONSTEXPR inline YUVLayout yuvLayout() const Q_DECL_NOTHROW { return YUVLayout(sub_enum); }
     Q_DECL_CONSTEXPR inline uchar subEnum() const Q_DECL_NOTHROW { return sub_enum; }
 
-protected:
+private:
     quint64 model : 4;
     quint64 first : 6;
     quint64 second : 6;