diff --git a/src/libs/cplusplus/TypeOfExpression.cpp b/src/libs/cplusplus/TypeOfExpression.cpp
index 1a58e080095b6e7cad937df562ad8058e7f9b45f..84d443f3bc29ce7c13b505dcd07250b75c84933b 100644
--- a/src/libs/cplusplus/TypeOfExpression.cpp
+++ b/src/libs/cplusplus/TypeOfExpression.cpp
@@ -139,7 +139,6 @@ QString TypeOfExpression::preprocessedExpression(const QString &expression,
                        &env, &processed);
     const QByteArray code = expression.toUtf8();
     Preprocessor preproc(0, env);
-    QByteArray preprocessedCode;
-    preproc("<expression>", code, &preprocessedCode);
+    const QByteArray preprocessedCode = preproc("<expression>", code);
     return QString::fromUtf8(preprocessedCode.constData(), preprocessedCode.size());
 }
diff --git a/src/libs/cplusplus/pp-engine.cpp b/src/libs/cplusplus/pp-engine.cpp
index fe7382875787f4da4135c08f23d14e178ddf39bd..c560451326fc864617ec765b5000f99eeae65f63 100644
--- a/src/libs/cplusplus/pp-engine.cpp
+++ b/src/libs/cplusplus/pp-engine.cpp
@@ -485,25 +485,25 @@ QByteArray Preprocessor::operator()(const QByteArray &filename,
                                     const QByteArray &source)
 {
     QByteArray preprocessed;
-    operator()(filename, source, &preprocessed);
+    preprocess(filename, source, &preprocessed);
     return preprocessed;
 }
 
 QByteArray Preprocessor::operator()(const QByteArray &source)
 {
     QByteArray preprocessed;
-    operator()(source, &preprocessed);
+    preprocess(source, &preprocessed);
     return preprocessed;
 }
 
-void Preprocessor::operator () (const QByteArray &filename,
-                      const QByteArray &source,
-                      QByteArray *result)
+void Preprocessor::preprocess(const QByteArray &filename,
+                              const QByteArray &source,
+                              QByteArray *result)
 {
     const QByteArray previousFile = env.currentFile;
     env.currentFile = filename;
 
-    operator () (source, result);
+    preprocess(source, result);
 
     env.currentFile = previousFile;
 }
@@ -523,7 +523,7 @@ Preprocessor::State Preprocessor::createStateFromSource(const QByteArray &source
     return state;
 }
 
-void Preprocessor::operator()(const QByteArray &source, QByteArray *result)
+void Preprocessor::preprocess(const QByteArray &source, QByteArray *result)
 {
     pushState(createStateFromSource(source));
 
diff --git a/src/libs/cplusplus/pp-engine.h b/src/libs/cplusplus/pp-engine.h
index 4fbbe1008d4b6e6736a1b1b156e381af987d4b80..706983dd12062ba6278b573f019db43f4947ddb5 100644
--- a/src/libs/cplusplus/pp-engine.h
+++ b/src/libs/cplusplus/pp-engine.h
@@ -186,14 +186,14 @@ namespace CPlusPlus {
 
         QByteArray operator()(const QByteArray &source);
 
-        void operator()(const QByteArray &filename,
+    private:
+        void preprocess(const QByteArray &filename,
                         const QByteArray &source,
                         QByteArray *result);
 
-        void operator()(const QByteArray &source,
+        void preprocess(const QByteArray &source,
                         QByteArray *result);
 
-    private:
         void resetIfLevel();
         bool testIfLevel();
         int skipping() const;
diff --git a/src/plugins/cpptools/cppmodelmanager.cpp b/src/plugins/cpptools/cppmodelmanager.cpp
index 1283699787eb01a44d3ea53fbe92513bd94c617f..6dc59f0d4d2cf920a8020cc4e7c3f46f594da878 100644
--- a/src/plugins/cpptools/cppmodelmanager.cpp
+++ b/src/plugins/cpptools/cppmodelmanager.cpp
@@ -202,7 +202,7 @@ protected:
 private:
     QPointer<CppModelManager> m_modelManager;
     Environment env;
-    Preprocessor m_proc;
+    Preprocessor preprocess;
     QStringList m_includePaths;
     QStringList m_systemIncludePaths;
     QMap<QString, QByteArray> m_workingCopy;
@@ -220,7 +220,7 @@ private:
 CppPreprocessor::CppPreprocessor(QPointer<CppModelManager> modelManager)
     : snapshot(modelManager->snapshot()),
       m_modelManager(modelManager),
-      m_proc(this, env)
+      preprocess(this, env)
 { }
 
 void CppPreprocessor::setWorkingCopy(const QMap<QString, QByteArray> &workingCopy)
@@ -506,8 +506,7 @@ void CppPreprocessor::sourceNeeded(QString &fileName, IncludeType type,
 
     Document::Ptr previousDoc = switchDocument(doc);
 
-    QByteArray preprocessedCode;
-    m_proc(fileName.toUtf8(), contents, &preprocessedCode);
+    const QByteArray preprocessedCode = preprocess(fileName.toUtf8(), contents);
 
     doc->setSource(preprocessedCode);
     doc->tokenize();