diff --git a/src/axis/qchartaxiscategories.cpp b/src/axis/qchartaxiscategories.cpp
index 6785eba..1f7d35b 100644
--- a/src/axis/qchartaxiscategories.cpp
+++ b/src/axis/qchartaxiscategories.cpp
@@ -13,10 +13,10 @@ QChartAxisCategories::~QChartAxisCategories()
     // TODO Auto-generated destructor stub
 }
 
-void QChartAxisCategories::insert(QBarCategory& category)
+void QChartAxisCategories::insert(const QBarCategories& categories)
 {
     int i=1;
-    foreach(QString string , category){
+    foreach(QString string , categories){
         m_map.insert(i,string);
         i++;
     }
diff --git a/src/axis/qchartaxiscategories.h b/src/axis/qchartaxiscategories.h
index 0dff8ae..897e611 100644
--- a/src/axis/qchartaxiscategories.h
+++ b/src/axis/qchartaxiscategories.h
@@ -14,7 +14,7 @@ private:
 public:
     ~QChartAxisCategories();
 
-    void insert(QBarCategory& category);
+    void insert(const QBarCategories& category);
     void insert(qreal value,QString label);
     void remove(qreal value);
     QString label(qreal value) const;
diff --git a/src/barchart/qbarseries.cpp b/src/barchart/qbarseries.cpp
index d4948df..9bb99c4 100644
--- a/src/barchart/qbarseries.cpp
+++ b/src/barchart/qbarseries.cpp
@@ -33,7 +33,7 @@ QTCOMMERCIALCHART_BEGIN_NAMESPACE
     Constructs empty QBarSeries. Parameter \a categories defines the categories for chart.
     QBarSeries is QObject which is a child of a \a parent.
 */
-QBarSeries::QBarSeries(QStringList categories, QObject *parent)
+QBarSeries::QBarSeries(QBarCategories categories, QObject *parent)
     : QSeries(parent)
     ,mModel(new BarChartModel(categories, this))
 {
@@ -365,6 +365,16 @@ void QBarSeries::barsetChanged()
     emit updatedBars();
 }
 
+QBarCategories QBarSeries::categories() const
+{
+    QBarCategories categories;
+    int count = mModel->categoryCount();
+    for (int i=1; i<=count; i++) {
+          categories.insert(i, mModel->categoryName(i-1));
+    }
+    return categories;
+}
+
 #include "moc_qbarseries.cpp"
 
 QTCOMMERCIALCHART_END_NAMESPACE
diff --git a/src/barchart/qbarseries.h b/src/barchart/qbarseries.h
index 846c450..23e5d96 100644
--- a/src/barchart/qbarseries.h
+++ b/src/barchart/qbarseries.h
@@ -6,7 +6,7 @@
 
 QTCOMMERCIALCHART_BEGIN_NAMESPACE
 
-typedef QStringList QBarCategory;
+typedef QStringList QBarCategories;
 
 class QBarSet;
 class BarChartModel;
@@ -29,6 +29,8 @@ public:
     int barsetCount();
     int categoryCount();
     QList<QBarSet*> barSets();
+    QBarCategories categories() const;
+
 
     bool setModel(QAbstractItemModel* model);
     QAbstractItemModel* modelExt() {return m_model;}
diff --git a/src/chartdataset.cpp b/src/chartdataset.cpp
index f9b6fda..1ba1dc5 100644
--- a/src/chartdataset.cpp
+++ b/src/chartdataset.cpp
@@ -240,12 +240,9 @@ void ChartDataSet::calculateDomain(QSeries* series,Domain* domain)
 
 void ChartDataSet::setupCategories(QBarSeries* series)
 {
-   int count = series->categoryCount();
    QChartAxisCategories* categories = axisX()->categories();
    categories->clear();
-   for (int i=1; i<=count; i++) {
-       categories->insert(i,series->categoryName(i-1));
-   }
+   categories->insert(series->categories());
 }
 
 void ChartDataSet::zoomInDomain(const QRectF& rect, const QSizeF& size)