diff --git a/tests/GroupPlotTest.cpp b/tests/GroupPlotTest.cpp
index 19ee3c8..ab3750f 100644
--- a/tests/GroupPlotTest.cpp
+++ b/tests/GroupPlotTest.cpp
@@ -19,10 +19,13 @@ void preparePlot(GroupPlot& plot)
         quantilesVector.push_back(quantiles);
     }
 
-    plot.setAxisScale(QwtPlot::yLeft, 0, 8);
-    plot.setAxisScale(QwtPlot::yRight, 0, 8);
-    plot.setAxisScale(QwtPlot::xBottom, 0.5, common::getValues().size() + 0.5,
-                      1);
+    const double maxValueForXAxis{8};
+    plot.setAxisScale(QwtPlot::yLeft, 0, maxValueForXAxis);
+    plot.setAxisScale(QwtPlot::yRight, 0, maxValueForXAxis);
+
+    const double maxValueForBottomAxis{
+        static_cast<double>(common::getValues().size()) + 0.5};
+    plot.setAxisScale(QwtPlot::xBottom, 0.5, maxValueForBottomAxis, 1);
     plot.setNewData(std::move(quantilesVector), common::getNames());
     plot.resize(common::getPlotSize());
 }
diff --git a/tests/QuantilesTest.cpp b/tests/QuantilesTest.cpp
index f4ba75a..5dbadf1 100644
--- a/tests/QuantilesTest.cpp
+++ b/tests/QuantilesTest.cpp
@@ -5,11 +5,11 @@
 
 #include <qwtble/Quantiles.h>
 
-void QuantilesTest::testToolTip()
+void QuantilesTest::testToolTip() const
 {
     Quantiles quantiles;
     quantiles.init(values_);
-    const QString expected(QStringLiteral(
+    const QString expected{QStringLiteral(
         "<table>"
         "<tr><td>Data count:</td><td ALIGN=RIGHT>11</td></tr>\n"
         "<tr><td>Average</td><td ALIGN=RIGHT>66.62</td></tr>\n"
@@ -21,22 +21,22 @@ void QuantilesTest::testToolTip()
         "<tr><td>Q10</td><td ALIGN=RIGHT>7.02</td></tr>\n"
         "<tr><td>Minimum</td><td ALIGN=RIGHT>5.00</td></tr>\n"
         "<tr><td>Std. deviation</td><td ALIGN=RIGHT>54.48</td></tr>\n"
-        "</table>"));
+        "</table>")};
     QCOMPARE(quantiles.getValuesAsToolTip(), expected);
 }
 
-void QuantilesTest::testToolTipForOneValue()
+void QuantilesTest::testToolTipForOneValue() const
 {
     Quantiles quantiles;
     const QVector<double> singleItemData{3};
     quantiles.init(singleItemData);
-    const QString expected(
+    const QString expected{
         QStringLiteral("<table>"
                        "<tr><td>Data count:</td><td ALIGN=RIGHT>1</td></tr>\n"
                        "<tr><td>Average</td><td ALIGN=RIGHT>3.00</td></tr>\n"
                        "<tr><td>Maximum</td><td ALIGN=RIGHT>3.00</td></tr>\n"
                        "<tr><td>Minimum</td><td ALIGN=RIGHT>3.00</td></tr>\n"
-                       "</table>"));
+                       "</table>")};
     QCOMPARE(quantiles.getValuesAsToolTip(), expected);
 }
 
diff --git a/tests/QuantilesTest.h b/tests/QuantilesTest.h
index 5abf86f..ebf596a 100644
--- a/tests/QuantilesTest.h
+++ b/tests/QuantilesTest.h
@@ -10,9 +10,9 @@ class QuantilesTest : public QObject
     QVector<double> values_{84.66,  40.,   5.,  7.02, 177.01, 110.23,
                             138.12, 54.94, 20., 80.,  15.85};
 private Q_SLOTS:
-    void testToolTip();
+    void testToolTip() const;
 
-    void testToolTipForOneValue();
+    void testToolTipForOneValue() const;
 
     void testComputing();