diff --git a/core/include/Data/DataSeries.h b/core/include/Data/DataSeries.h
index c258397..2087a94 100644
--- a/core/include/Data/DataSeries.h
+++ b/core/include/Data/DataSeries.h
@@ -193,6 +193,9 @@ public:
     /// @sa IDataSeries::xAxisUnit()
     Unit xAxisUnit() const override { return m_XAxisUnit; }
 
+    /// @sa IDataSeries::yAxisUnit()
+    Unit yAxisUnit() const override { return m_YAxis.unit(); }
+
     /// @return the values dataset
     std::shared_ptr<ArrayData<Dim> > valuesData() { return m_ValuesData; }
     const std::shared_ptr<ArrayData<Dim> > valuesData() const { return m_ValuesData; }
@@ -202,6 +205,8 @@ public:
 
     int nbPoints() const override { return m_ValuesData->totalSize(); }
 
+    std::pair<double, double> yBounds() const override { return m_YAxis.bounds(); }
+
     void clear()
     {
         m_XAxisData->clear();
@@ -384,8 +389,8 @@ public:
     }
 
     /// @return the y-axis associated to the data series
-    /// @todo pass getter as protected and use iterators to access the y-axis data
-    OptionalAxis yAxis() const { return m_YAxis; }
+    const OptionalAxis &yAxis() const { return m_YAxis; }
+    OptionalAxis &yAxis() { return m_YAxis; }
 
     // /////// //
     // Mutexes //
diff --git a/core/include/Data/IDataSeries.h b/core/include/Data/IDataSeries.h
index 44ed1dd..c16f6c4 100644
--- a/core/include/Data/IDataSeries.h
+++ b/core/include/Data/IDataSeries.h
@@ -39,6 +39,9 @@ public:
 
     virtual Unit xAxisUnit() const = 0;
 
+    /// @return the y-axis unit, if axis is defined, default unit otherwise
+    virtual Unit yAxisUnit() const = 0;
+
     virtual Unit valuesUnit() const = 0;
 
     virtual void merge(IDataSeries *dataSeries) = 0;
@@ -53,6 +56,9 @@ public:
     /// @return the total number of points contained in the data series
     virtual int nbPoints() const = 0;
 
+    /// @return the bounds of the y-axis axis (if defined)
+    virtual std::pair<double, double> yBounds() const = 0;
+
     // ///////// //
     // Iterators //
     // ///////// //
diff --git a/gui/src/Visualization/AxisRenderingUtils.cpp b/gui/src/Visualization/AxisRenderingUtils.cpp
index 869fbbc..4f300b9 100644
--- a/gui/src/Visualization/AxisRenderingUtils.cpp
+++ b/gui/src/Visualization/AxisRenderingUtils.cpp
@@ -101,8 +101,7 @@ struct AxisSetter<T, typename std::enable_if_t<std::is_base_of<SpectrogramSeries
     {
         dataSeries.lockRead();
         auto xAxisUnit = dataSeries.xAxisUnit();
-        /// @todo ALX: use iterators here
-        auto yAxisUnit = dataSeries.yAxis().unit();
+        auto yAxisUnit = dataSeries.yAxisUnit();
         auto valuesUnit = dataSeries.valuesUnit();
         dataSeries.unlock();
 
diff --git a/gui/src/Visualization/VisualizationGraphHelper.cpp b/gui/src/Visualization/VisualizationGraphHelper.cpp
index fe6b244..47992bc 100644
--- a/gui/src/Visualization/VisualizationGraphHelper.cpp
+++ b/gui/src/Visualization/VisualizationGraphHelper.cpp
@@ -180,8 +180,7 @@ struct PlottablesUpdater<T,
     static void setPlotYAxisRange(T &dataSeries, const SqpRange &xAxisRange, QCustomPlot &plot)
     {
         double min, max;
-        /// @todo ALX: use iterators here
-        std::tie(min, max) = dataSeries.yAxis().bounds();
+        std::tie(min, max) = dataSeries.yBounds();
 
         if (!std::isnan(min) && !std::isnan(max)) {
             plot.yAxis->setRange(QCPRange{min, max});