diff --git a/src/barplot.cpp b/src/barplot.cpp
--- a/src/barplot.cpp
+++ b/src/barplot.cpp
@@ -35,7 +35,8 @@ BarPlot::BarPlot(ChannelManager* channel
 
 void BarPlot::update()
 {
-    setAxisScale(QwtPlot::xBottom, 0, _channelMan->numOfChannels(), 1);
+    // Note: -0.99 is used instead of -1 to handle the case of `numOfChannels==1`
+    setAxisScale(QwtPlot::xBottom, 0, _channelMan->numOfChannels()-0.99, 1);
     barChart.resample();
     replot();
 }