diff --git a/src/app/qgsdiagramproperties.cpp b/src/app/qgsdiagramproperties.cpp
index e635b7650f85..c736482c528b 100644
--- a/src/app/qgsdiagramproperties.cpp
+++ b/src/app/qgsdiagramproperties.cpp
@@ -338,20 +338,6 @@ void QgsDiagramProperties::on_mDiagramTypeComboBox_currentIndexChanged( const QS
   }
 }
 
-void QgsDiagramProperties::on_mIncreaseSmallDiagramsCheckBox_stateChanged( int state )
-{
-  if ( Qt::Checked == state )
-  {
-    mIncreaseMinimumSizeLabel->setEnabled( true );
-    mIncreaseMinimumSizeSpinBox->setEnabled( true );
-  }
-  else
-  {
-    mIncreaseMinimumSizeLabel->setEnabled( false );
-    mIncreaseMinimumSizeSpinBox->setEnabled( false );
-  }
-}
-
 void QgsDiagramProperties::on_mTransparencySlider_valueChanged( int value )
 {
   mTransparencyLabel->setText( tr( "Transparency: %1%" ).arg( value ) );
@@ -610,4 +596,4 @@ void QgsDiagramProperties::apply()
     }
     mLayer->setDiagramLayerSettings( dls );
   }
-}
\ No newline at end of file
+}
diff --git a/src/app/qgsdiagramproperties.h b/src/app/qgsdiagramproperties.h
index b27419a42e13..3b82fafde70a 100644
--- a/src/app/qgsdiagramproperties.h
+++ b/src/app/qgsdiagramproperties.h
@@ -35,7 +35,6 @@ class QgsDiagramProperties : public QWidget, private Ui::QgsDiagramPropertiesBas
   public slots:
     void apply();
     void on_mDiagramTypeComboBox_currentIndexChanged( const QString& itemtext );
-    void on_mIncreaseSmallDiagramsCheckBox_stateChanged( int state );
     void on_mTransparencySlider_valueChanged( int value );
     void on_mAddCategoryPushButton_clicked();
     void on_mBackgroundColorButton_clicked();