diff --git a/src/corelib/tools/qbytearray.h b/src/corelib/tools/qbytearray.h
index 14fcddce7ca..d21cb9b3638 100644
--- a/src/corelib/tools/qbytearray.h
+++ b/src/corelib/tools/qbytearray.h
@@ -528,7 +528,11 @@ inline void QByteArray::squeeze()
     }
 }
 
-class Q_CORE_EXPORT QByteRef {
+class
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+Q_CORE_EXPORT
+#endif
+QByteRef {
     QByteArray &a;
     int i;
     inline QByteRef(QByteArray &array, int idx)
diff --git a/src/corelib/tools/qstring.h b/src/corelib/tools/qstring.h
index 9d75b0f357c..1abb91eabe8 100644
--- a/src/corelib/tools/qstring.h
+++ b/src/corelib/tools/qstring.h
@@ -1044,8 +1044,11 @@ inline QString QString::fromWCharArray(const wchar_t *string, int size)
                                             : fromUcs4(reinterpret_cast<const uint *>(string), size);
 }
 
-
-class Q_CORE_EXPORT QCharRef {
+class
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+Q_CORE_EXPORT
+#endif
+QCharRef {
     QString &s;
     int i;
     inline QCharRef(QString &str, int idx)