diff --git a/zoomer.cpp b/zoomer.cpp
new file mode 100644
--- /dev/null
+++ b/zoomer.cpp
@@ -0,0 +1,44 @@
+/*
+  Copyright © 2015 Hasan Yavuz Özderya
+
+  This file is part of serialplot.
+
+  serialplot is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  serialplot is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with serialplot.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "zoomer.h"
+#include <qwt_plot.h>
+#include <QtDebug>
+
+Zoomer::Zoomer(QWidget* widget, bool doReplot) :
+    QwtPlotZoomer(widget, doReplot)
+{
+    // do nothing
+}
+
+void Zoomer::zoom(int up)
+{
+    if (up == +1)
+    {
+        this->setZoomBase(this->plot());
+    }
+
+    QwtPlotZoomer::zoom(up);
+
+    if (up == 0)
+    {
+        this->plot()->setAxisAutoScale(QwtPlot::yLeft);
+        this->plot()->replot();
+    }
+}