diff --git a/src/corelib/serialization/qcborvalue.h b/src/corelib/serialization/qcborvalue.h
index b90d397bcc..aeac764780 100644
--- a/src/corelib/serialization/qcborvalue.h
+++ b/src/corelib/serialization/qcborvalue.h
@@ -428,6 +428,8 @@ protected:
     qsizetype i;
 };
 
+QT_WARNING_PUSH
+QT6_ONLY(QT_WARNING_DISABLE_MSVC(4275)) // non dll-interface class 'QJsonValueConstRef' used as base for dll-interface class 'QJsonValueRef'
 class QT6_ONLY(Q_CORE_EXPORT) QCborValueRef : public QCborValueConstRef
 {
 public:
@@ -582,6 +584,7 @@ private:
     QT7_ONLY(Q_CORE_EXPORT) static void assign(QCborValueRef that, QCborValue &&other);
     QT7_ONLY(Q_CORE_EXPORT) static void assign(QCborValueRef that, const QCborValueRef other);
 };
+QT_WARNING_POP
 Q_DECLARE_OPERATORS_FOR_FLAGS(QCborValue::EncodingOptions)
 Q_DECLARE_OPERATORS_FOR_FLAGS(QCborValue::DiagnosticNotationOptions)
 
diff --git a/src/corelib/serialization/qjsonvalue.h b/src/corelib/serialization/qjsonvalue.h
index dddc8a0c30..b0b6b97fab 100644
--- a/src/corelib/serialization/qjsonvalue.h
+++ b/src/corelib/serialization/qjsonvalue.h
@@ -215,6 +215,8 @@ protected:
     friend class QJsonPrivate::Value;
 };
 
+QT_WARNING_PUSH
+QT6_ONLY(QT_WARNING_DISABLE_MSVC(4275)) // non dll-interface class 'QJsonValueConstRef' used as base for dll-interface class 'QJsonValueRef'
 class QT6_ONLY(Q_CORE_EXPORT) QJsonValueRef : public QJsonValueConstRef
 {
 public:
@@ -273,6 +275,7 @@ private:
     friend class QJsonArray;
     friend class QJsonObject;
 };
+QT_WARNING_POP
 
 inline QJsonValue QCborValueConstRef::toJsonValue() const
 {