diff --git a/src/libs/qmljs/parser/qmljsengine_p.cpp b/src/libs/qmljs/parser/qmljsengine_p.cpp
index 29456b8156e..44f03a1a740 100644
--- a/src/libs/qmljs/parser/qmljsengine_p.cpp
+++ b/src/libs/qmljs/parser/qmljsengine_p.cpp
@@ -133,13 +133,14 @@ MemoryPool *Engine::pool()
 
 QStringView Engine::newStringRef(const QString &text)
 {
-    const int pos = _extraCode.length();
-    _extraCode += text;
-    return Utils::midView(_extraCode, pos, text.length());
+    _extraCode.append(text);
+    return QStringView{_extraCode.last()};
 }
 
 QStringView Engine::newStringRef(const QChar *chars, int size)
-{ return newStringRef(QString(chars, size)); }
+{
+    return newStringRef(QString(chars, size));
+}
 
 } // end of namespace QmlJS
 
diff --git a/src/libs/qmljs/parser/qmljsengine_p.h b/src/libs/qmljs/parser/qmljsengine_p.h
index acef6c015b6..a6e8ad272f9 100644
--- a/src/libs/qmljs/parser/qmljsengine_p.h
+++ b/src/libs/qmljs/parser/qmljsengine_p.h
@@ -37,14 +37,16 @@
 //
 
 #include "qmljsglobal_p.h"
-#include "qmljs/parser/qmljssourcelocation_p.h"
 
 #include "qmljs/parser/qmljsmemorypool_p.h"
+#include "qmljs/parser/qmljssourcelocation_p.h"
+#include <qmljs/qmljsconstants.h>
+
+#include <utils/porting.h>
 
 #include <QString>
 #include <QSet>
 
-#include <qmljs/qmljsconstants.h>
 QT_QML_BEGIN_NAMESPACE
 
 namespace QmlJS {
@@ -84,7 +86,7 @@ class QML_PARSER_EXPORT Engine
     Directives *_directives;
     MemoryPool _pool;
     QList<SourceLocation> _comments;
-    QString _extraCode;
+    QStringList _extraCode;
     QString _code;
 
 public:
@@ -107,9 +109,7 @@ public:
 
     inline QStringView midRef(int position, int size)
     {
-        if (position + size > _code.size())
-            return QStringView(_code).mid(position);
-        return QStringView(_code).mid(position, size);
+        return Utils::midView(_code, position, size);
     }
 
     QStringView newStringRef(const QString &s);