diff --git a/src/barchart/qbarmodelmapper.h b/src/barchart/qbarmodelmapper.h
index 82c3e8f..c9b5f2d 100644
--- a/src/barchart/qbarmodelmapper.h
+++ b/src/barchart/qbarmodelmapper.h
@@ -30,7 +30,6 @@ QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
 class QBarModelMapperPrivate;
 class QAbstractBarSeries;
-class QChart;
 
 class QTCOMMERCIALCHART_EXPORT QBarModelMapper : public QObject
 {
diff --git a/src/barchart/qbarmodelmapper_p.h b/src/barchart/qbarmodelmapper_p.h
index e1d931d..e163ae5 100644
--- a/src/barchart/qbarmodelmapper_p.h
+++ b/src/barchart/qbarmodelmapper_p.h
@@ -30,7 +30,6 @@
 #ifndef QBARMODELMAPPER_P_H
 #define QBARMODELMAPPER_P_H
 
-#include "qchartglobal.h"
 #include <QObject>
 #include "qbarmodelmapper.h"
 
diff --git a/src/piechart/qpiemodelmapper.h b/src/piechart/qpiemodelmapper.h
index cb01d63..a8f4cee 100644
--- a/src/piechart/qpiemodelmapper.h
+++ b/src/piechart/qpiemodelmapper.h
@@ -36,7 +36,7 @@ class QTCOMMERCIALCHART_EXPORT QPieModelMapper : public QObject
     Q_OBJECT
 
 protected:
-    QPieModelMapper(QObject *parent = 0);
+    explicit QPieModelMapper(QObject *parent = 0);
 
     QAbstractItemModel* model() const;
     void setModel(QAbstractItemModel *model);
diff --git a/src/piechart/qpiemodelmapper_p.h b/src/piechart/qpiemodelmapper_p.h
index ac32d5b..c0422ef 100644
--- a/src/piechart/qpiemodelmapper_p.h
+++ b/src/piechart/qpiemodelmapper_p.h
@@ -30,16 +30,13 @@
 #ifndef QPIEMODELMAPPER_P_H
 #define QPIEMODELMAPPER_P_H
 
-#include "qpiemodelmapper.h"
 #include <QObject>
+#include "qpiemodelmapper.h"
 
 class QModelIndex;
-class QAbstractItemModel;
 
 QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
-class QPieModelMapper;
-class QPieSeries;
 class QPieSlice;
 
 class QPieModelMapperPrivate : public QObject
@@ -47,7 +44,7 @@ class QPieModelMapperPrivate : public QObject
     Q_OBJECT
 
 public:
-    QPieModelMapperPrivate(QPieModelMapper *q);
+    explicit QPieModelMapperPrivate(QPieModelMapper *q);
 
 public Q_SLOTS:
     // for the model
@@ -95,7 +92,6 @@ private:
 
     QPieModelMapper *q_ptr;
     Q_DECLARE_PUBLIC(QPieModelMapper)
-    friend class QPieSeriesPrivate;
 };
 
 QTCOMMERCIALCHART_END_NAMESPACE