diff --git a/src/plugins/cpptools/cppfindreferences.cpp b/src/plugins/cpptools/cppfindreferences.cpp
index d580c89c0e1e45cf87ae20e38923c7fd8221425c..8758a9f4b4a8e150c8768a40bd850ce337ba0767 100644
--- a/src/plugins/cpptools/cppfindreferences.cpp
+++ b/src/plugins/cpptools/cppfindreferences.cpp
@@ -68,15 +68,15 @@ namespace {
 
 class ProcessFile: public std::unary_function<QString, QList<Usage> >
 {
-    const QHash<QString, QString> workingList;
+    const CppTools::CppModelManagerInterface::WorkingCopy workingCopy;
     const Snapshot snapshot;
     Symbol *symbol;
 
 public:
-    ProcessFile(const QHash<QString, QString> workingList,
-              const Snapshot snapshot,
-              Symbol *symbol)
-        : workingList(workingList), snapshot(snapshot), symbol(symbol)
+    ProcessFile(const CppTools::CppModelManagerInterface::WorkingCopy &workingCopy,
+                const Snapshot snapshot,
+                Symbol *symbol)
+        : workingCopy(workingCopy), snapshot(snapshot), symbol(symbol)
     { }
 
     QList<Usage> operator()(const QString &fileName)
@@ -92,8 +92,8 @@ public:
 
         QByteArray source;
 
-        if (workingList.contains(fileName))
-            source = snapshot.preprocessedCode(workingList.value(fileName), fileName);
+        if (workingCopy.contains(fileName))
+            source = snapshot.preprocessedCode(workingCopy.source(fileName), fileName);
         else {
             QFile file(fileName);
             if (! file.open(QFile::ReadOnly))
@@ -168,7 +168,7 @@ QList<int> CppFindReferences::references(Symbol *symbol,
 }
 
 static void find_helper(QFutureInterface<Usage> &future,
-                        const QHash<QString, QString> workingList,
+                        const CppTools::CppModelManagerInterface::WorkingCopy workingCopy,
                         Snapshot snapshot,
                         Symbol *symbol)
 {
@@ -199,7 +199,7 @@ static void find_helper(QFutureInterface<Usage> &future,
 
     future.setProgressRange(0, files.size());
 
-    ProcessFile process(workingList, snapshot, symbol);
+    ProcessFile process(workingCopy, snapshot, symbol);
     UpdateUI reduce(&future);
 
     QtConcurrent::blockingMappedReduced<QList<Usage> > (files, process, reduce);
diff --git a/src/plugins/cpptools/cppmodelmanager.cpp b/src/plugins/cpptools/cppmodelmanager.cpp
index 4c60a5d312d7469132c68b89256cfc1647a0cbf4..8a947f1205adf3aa0b1674df219809b7501c9f20 100644
--- a/src/plugins/cpptools/cppmodelmanager.cpp
+++ b/src/plugins/cpptools/cppmodelmanager.cpp
@@ -171,7 +171,7 @@ public:
     virtual ~CppPreprocessor();
 
     void setRevision(unsigned revision);
-    void setWorkingCopy(const QHash<QString, QString> &workingCopy);
+    void setWorkingCopy(const CppModelManagerInterface::WorkingCopy &workingCopy);
     void setIncludePaths(const QStringList &includePaths);
     void setFrameworkPaths(const QStringList &frameworkPaths);
     void setProjectFiles(const QStringList &files);
@@ -215,7 +215,7 @@ private:
     Preprocessor preprocess;
     QStringList m_includePaths;
     QStringList m_systemIncludePaths;
-    QHash<QString, QString> m_workingCopy;
+    CppModelManagerInterface::WorkingCopy m_workingCopy;
     QStringList m_projectFiles;
     QStringList m_frameworkPaths;
     QSet<QString> m_included;
@@ -241,7 +241,7 @@ CppPreprocessor::~CppPreprocessor()
 void CppPreprocessor::setRevision(unsigned revision)
 { m_revision = revision; }
 
-void CppPreprocessor::setWorkingCopy(const QHash<QString, QString> &workingCopy)
+void CppPreprocessor::setWorkingCopy(const CppTools::CppModelManagerInterface::WorkingCopy &workingCopy)
 { m_workingCopy = workingCopy; }
 
 void CppPreprocessor::setIncludePaths(const QStringList &includePaths)
@@ -263,13 +263,13 @@ class Process: public std::unary_function<Document::Ptr, void>
 {
     QPointer<CppModelManager> _modelManager;
     Snapshot _snapshot;
-    QHash<QString, QString> _workingCopy;
+    CppModelManager::WorkingCopy _workingCopy;
     Document::Ptr _doc;
 
 public:
     Process(QPointer<CppModelManager> modelManager,
             Snapshot snapshot,
-            const QHash<QString, QString> &workingCopy)
+            const CppModelManager::WorkingCopy &workingCopy)
         : _modelManager(modelManager),
           _snapshot(snapshot),
           _workingCopy(workingCopy)
@@ -335,7 +335,7 @@ bool CppPreprocessor::includeFile(const QString &absoluteFilePath, QString *resu
 
     if (m_workingCopy.contains(absoluteFilePath)) {
         m_included.insert(absoluteFilePath);
-        *result = m_workingCopy.value(absoluteFilePath);
+        *result = m_workingCopy.source(absoluteFilePath);
         return true;
     }
 
@@ -797,19 +797,19 @@ CppModelManager::WorkingCopy CppModelManager::buildWorkingCopyList()
         TextEditor::ITextEditor *textEditor = it.key();
         CppEditorSupport *editorSupport = it.value();
         QString fileName = textEditor->file()->fileName();
-        workingCopy[fileName] = editorSupport->contents();
+        workingCopy.insert(fileName, editorSupport->contents());
     }
 
     QSetIterator<AbstractEditorSupport *> jt(m_addtionalEditorSupport);
     while (jt.hasNext()) {
         AbstractEditorSupport *es =  jt.next();
-        workingCopy[es->fileName()] = es->contents();
+        workingCopy.insert(es->fileName(), es->contents());
     }
 
     // add the project configuration file
     QByteArray conf(pp_configuration);
     conf += definedMacros();
-    workingCopy[pp_configuration_file] = conf;
+    workingCopy.insert(pp_configuration_file, conf);
 
     return workingCopy;
 }
diff --git a/src/plugins/cpptools/cppmodelmanagerinterface.h b/src/plugins/cpptools/cppmodelmanagerinterface.h
index f0327fb631ee759daec98decc567cb1440a64747..77ed5f8e73e0b473cd6c1ce6860803d7b61e1c05 100644
--- a/src/plugins/cpptools/cppmodelmanagerinterface.h
+++ b/src/plugins/cpptools/cppmodelmanagerinterface.h
@@ -78,7 +78,30 @@ public:
         QStringList frameworkPaths;
     };
 
-    typedef QHash<QString, QString> WorkingCopy;
+    class WorkingCopy
+    {
+    public:
+        typedef QHash<QString, QString> Table;
+
+        typedef Table::const_iterator iterator;
+        typedef Table::const_iterator const_iterator;
+
+    public:
+        const_iterator begin() const { return _elements.begin(); }
+        const_iterator end() const { return _elements.end(); }
+
+        void insert(const QString &fileName, const QString &source)
+        { _elements.insert(fileName, source); }
+
+        bool contains(const QString &fileName) const
+        { return _elements.contains(fileName); }
+
+        QString source(const QString &fileName) const
+        { return _elements.value(fileName); }
+
+    private:
+        Table _elements;
+    };
 
 public:
     CppModelManagerInterface(QObject *parent = 0) : QObject(parent) {}