diff --git a/mainwindow.cpp b/mainwindow.cpp
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -137,6 +137,8 @@ MainWindow::MainWindow(QWidget *parent) 
     // init zoomer
     zoomer = new Zoomer(ui->plot->canvas(), false);
     zoomer->setZoomBase();
+    QObject::connect(zoomer, &Zoomer::unzoomed,
+                     this, &MainWindow::unzoomed);
 
     // init number format
     if (numberFormatButtons.checkedId() >= 0)
@@ -731,3 +733,18 @@ void MainWindow::messageHandler(QtMsgTyp
         ui->statusBar->showMessage(msg, 5000);
     }
 }
+
+void MainWindow::unzoomed()
+{
+    if (ui->cbAutoScale->isChecked())
+    {
+        ui->plot->setAxisAutoScale(QwtPlot::yLeft);
+    }
+    else
+    {
+        ui->plot->setAxisScale(QwtPlot::yLeft, ui->spYmin->value(),
+                               ui->spYmax->value());
+    }
+    ui->plot->setAxisAutoScale(QwtPlot::xBottom);
+    ui->plot->replot();
+}
diff --git a/mainwindow.h b/mainwindow.h
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -87,6 +87,7 @@ private:
     void addChannelData(unsigned int channel, DataArray data);
 
     Zoomer* zoomer;
+    void unzoomed();
 
     NumberFormat numberFormat;
     unsigned int sampleSize; // number of bytes in the selected number format
diff --git a/zoomer.cpp b/zoomer.cpp
--- a/zoomer.cpp
+++ b/zoomer.cpp
@@ -38,7 +38,6 @@ void Zoomer::zoom(int up)
 
     if (up == 0)
     {
-        this->plot()->setAxisAutoScale(QwtPlot::yLeft);
-        this->plot()->replot();
+        emit unzoomed();
     }
 }
diff --git a/zoomer.h b/zoomer.h
--- a/zoomer.h
+++ b/zoomer.h
@@ -29,6 +29,9 @@ class Zoomer : public QwtPlotZoomer
 public:
     Zoomer(QWidget *, bool doReplot=true);
     void zoom(int up);
+
+signals:
+    void unzoomed();
 };
 
 #endif // ZOOMER_H