diff --git a/src/plugins/cpptools/stringtable.cpp b/src/plugins/cpptools/stringtable.cpp
index d3a9f51a2af..e27fc5ceaef 100644
--- a/src/plugins/cpptools/stringtable.cpp
+++ b/src/plugins/cpptools/stringtable.cpp
@@ -124,8 +124,13 @@ StringTable::~StringTable()
 
 static inline bool isQStringInUse(const QString &string)
 {
-    QArrayData *data_ptr = const_cast<QString&>(string).data_ptr();
-    return data_ptr->ref.isShared() || data_ptr->ref.isStatic();
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
+    auto data_ptr = const_cast<QString&>(string).data_ptr();
+    return data_ptr->ref.isShared() || data_ptr->ref.isStatic() /* QStringLiteral ? */;
+#else
+    auto data_ptr = const_cast<QString&>(string).data_ptr();
+    return data_ptr->isShared() || !data_ptr->isMutable() /* QStringLiteral ? */;
+#endif
 }
 
 void StringTablePrivate::GC()