diff --git a/src/corelib/global/qflags.h b/src/corelib/global/qflags.h
index dc187ef4f65..0ec7f4383f5 100644
--- a/src/corelib/global/qflags.h
+++ b/src/corelib/global/qflags.h
@@ -206,8 +206,10 @@ private:
         return (it == end ? Int(0) : (Int(*it) | initializer_list_helper(it + 1, end)));
     }
 
+#ifndef QT_NO_DATASTREAM
     template <typename E> friend QDataStream &operator<<(QDataStream &, QFlags<E>);
     template <typename E> friend QDataStream &operator>>(QDataStream &, QFlags<E> &);
+#endif
     using Base::i;
 };