diff --git a/plugins/extensions/histogram/kis_histogram_widget.h b/plugins/extensions/histogram/kis_histogram_widget.h
--- a/plugins/extensions/histogram/kis_histogram_widget.h
+++ b/plugins/extensions/histogram/kis_histogram_widget.h
@@ -49,7 +49,7 @@
 
 private Q_SLOTS:
     void setActiveChannel(int channel);
-    void slotTypeSwitched(int id);
+    void slotTypeSwitched(void);
     void slotZoomIn();
     void slotZoomOut();
     void slide(int val);
diff --git a/plugins/extensions/histogram/kis_histogram_widget.cc b/plugins/extensions/histogram/kis_histogram_widget.cc
--- a/plugins/extensions/histogram/kis_histogram_widget.cc
+++ b/plugins/extensions/histogram/kis_histogram_widget.cc
@@ -71,7 +71,8 @@
     m_from = m_histogramView->currentProducer()->viewFrom();
     m_width = m_histogramView->currentProducer()->viewWidth();
 
-    connect(grpType, SIGNAL(clicked(int)), this, SLOT(slotTypeSwitched(int)));
+    connect(radioLinear,SIGNAL(clicked()), this, SLOT(slotTypeSwitched()));
+    connect(radioLog,SIGNAL(clicked()), this, SLOT(slotTypeSwitched()));
     connect(cmbChannel, SIGNAL(activated(int)), this, SLOT(setActiveChannel(int)));
     connect(zoomIn, SIGNAL(clicked()), this, SLOT(slotZoomIn()));
     connect(zoomOut, SIGNAL(clicked()), this, SLOT(slotZoomOut()));
@@ -84,12 +85,9 @@
     updateEnabled();
 }
 
-void KisHistogramWidget::slotTypeSwitched(int id)
+void KisHistogramWidget::slotTypeSwitched(void)
 {
-    if (id == LINEAR)
-        m_histogramView->setHistogramType(LINEAR);
-    else if (id == LOGARITHMIC)
-        m_histogramView->setHistogramType(LOGARITHMIC);
+    m_histogramView->setHistogramType( radioLinear->isChecked()?LINEAR:LOGARITHMIC );
 }
 
 void KisHistogramWidget::setView(double from, double size)