diff --git a/src/corelib/tools/qbitarray.h b/src/corelib/tools/qbitarray.h
index f38ee3ddcd2..a37f333f3ea 100644
--- a/src/corelib/tools/qbitarray.h
+++ b/src/corelib/tools/qbitarray.h
@@ -110,7 +110,7 @@ public:
     inline const DataPtr &data_ptr() const { return d.data_ptr(); }
 };
 
-class Q_CORE_EXPORT QBitRef
+class QT6_ONLY(Q_CORE_EXPORT) QBitRef
 {
 private:
     QBitArray &a;