diff --git a/src/plugins/coreplugin/editormanager/editormanager.cpp b/src/plugins/coreplugin/editormanager/editormanager.cpp
index d2bddb8a014..16980f59e44 100644
--- a/src/plugins/coreplugin/editormanager/editormanager.cpp
+++ b/src/plugins/coreplugin/editormanager/editormanager.cpp
@@ -1981,7 +1981,7 @@ QByteArray EditorManager::saveState() const
 
     foreach (const OpenEditorsModel::Entry &entry, entries) {
         if (!entry.editor || !entry.editor->isTemporary())
-            stream << entry.fileName() << entry.displayName() << entry.id().name();
+            stream << entry.fileName() << entry.displayName() << entry.id();
     }
 
     stream << d->m_splitter->saveState();
@@ -2012,7 +2012,7 @@ bool EditorManager::restoreState(const QByteArray &state)
         stream >> fileName;
         QString displayName;
         stream >> displayName;
-        QByteArray id;
+        Core::Id id;
         stream >> id;
 
         if (!fileName.isEmpty() && !displayName.isEmpty()) {
@@ -2021,9 +2021,9 @@ bool EditorManager::restoreState(const QByteArray &state)
                 continue;
             QFileInfo rfi(autoSaveName(fileName));
             if (rfi.exists() && fi.lastModified() < rfi.lastModified())
-                openEditor(fileName, Id::fromName(id));
+                openEditor(fileName, id);
             else
-                d->m_editorModel->addRestoredEditor(fileName, displayName, Id::fromName(id));
+                d->m_editorModel->addRestoredEditor(fileName, displayName, id);
         }
     }
 
diff --git a/src/plugins/coreplugin/id.cpp b/src/plugins/coreplugin/id.cpp
index 407c9b801c2..d32cc4c8b35 100644
--- a/src/plugins/coreplugin/id.cpp
+++ b/src/plugins/coreplugin/id.cpp
@@ -354,3 +354,21 @@ QString Id::suffixAfter(Id baseId) const
 }
 
 } // namespace Core
+
+
+QT_BEGIN_NAMESPACE
+
+QDataStream &operator<<(QDataStream &ds, const Core::Id &id)
+{
+    return ds << id.name();
+}
+
+QDataStream &operator>>(QDataStream &ds, Core::Id &id)
+{
+    QByteArray ba;
+    ds >> ba;
+    id = Core::Id::fromName(ba);
+    return ds;
+}
+
+QT_END_NAMESPACE
diff --git a/src/plugins/coreplugin/id.h b/src/plugins/coreplugin/id.h
index ee283a5f9ad..bb43fd01431 100644
--- a/src/plugins/coreplugin/id.h
+++ b/src/plugins/coreplugin/id.h
@@ -86,4 +86,9 @@ inline uint qHash(const Id &id) { return id.uniqueIdentifier(); }
 Q_DECLARE_METATYPE(Core::Id)
 Q_DECLARE_METATYPE(QList<Core::Id>)
 
+QT_BEGIN_NAMESPACE
+QDataStream &operator<<(QDataStream &ds, const Core::Id &id);
+QDataStream &operator>>(QDataStream &ds, Core::Id &id);
+QT_END_NAMESPACE
+
 #endif // CORE_ID_H