diff --git a/tests/boxplottester/mainwidget.cpp b/tests/boxplottester/mainwidget.cpp
index 2f95d14..4890b1f 100644
--- a/tests/boxplottester/mainwidget.cpp
+++ b/tests/boxplottester/mainwidget.cpp
@@ -366,7 +366,10 @@ void MainWidget::setBrush()
 
     if (m_seriesCount > 0) {
         QList<QBoxSet *> sets = m_series[0]->boxSets();
-        sets.at(1)->setBrush(QBrush(QColor(Qt::yellow)));
+        if (sets.count() > 1)
+            sets.at(1)->setBrush(QBrush(QColor(Qt::yellow)));
+        else
+            qDebug() << "Create a series with at least two items first";
     } else {
         qDebug() << "Create a series first";
     }