diff --git a/src/corelib/global/qflags.h b/src/corelib/global/qflags.h
index cf0cd4b155..2319a78877 100644
--- a/src/corelib/global/qflags.h
+++ b/src/corelib/global/qflags.h
@@ -97,8 +97,6 @@ class QFlags
     struct Private;
     typedef int (Private::*Zero);
 #endif
-    template <typename E> friend QDataStream &operator>>(QDataStream &, QFlags<E> &);
-    template <typename E> friend QDataStream &operator<<(QDataStream &, QFlags<E>);
 public:
 #if defined(Q_CC_MSVC) || defined(Q_CLANG_QDOC)
     // see above for MSVC
diff --git a/src/corelib/serialization/qdatastream.h b/src/corelib/serialization/qdatastream.h
index 93eaaff43b..3a234ab15e 100644
--- a/src/corelib/serialization/qdatastream.h
+++ b/src/corelib/serialization/qdatastream.h
@@ -396,11 +396,16 @@ inline QDataStream &QDataStream::operator<<(quint64 i)
 
 template <typename Enum>
 inline QDataStream &operator<<(QDataStream &s, QFlags<Enum> e)
-{ return s << e.i; }
+{ return s << typename QFlags<Enum>::Int(e); }
 
 template <typename Enum>
 inline QDataStream &operator>>(QDataStream &s, QFlags<Enum> &e)
-{ return s >> e.i; }
+{
+    typename QFlags<Enum>::Int i;
+    s >> i;
+    e = QFlag(i);
+    return s;
+}
 
 template <typename T>
 typename std::enable_if_t<std::is_enum<T>::value, QDataStream &>