diff --git a/src/qtui/chatview.cpp b/src/qtui/chatview.cpp
index 704b3bea..e82e3ed3 100644
--- a/src/qtui/chatview.cpp
+++ b/src/qtui/chatview.cpp
@@ -208,6 +208,19 @@ void ChatView::adjustSceneRect()
 }
 
 
+void ChatView::setPageStep()
+{
+	auto line = _scene->chatItemAt(QPointF(0, 0));
+	if (line) {
+		qreal line_height = line->height();
+		int viewport_height = viewport()->size().height();
+		int context = 2;
+
+		verticalScrollBar()->setPageStep(viewport_height - context * line_height);
+	}
+}
+
+
 void ChatView::mouseMoveWhileSelecting(const QPointF &scenePos)
 {
     int y = (int)mapFromScene(scenePos).y();
@@ -394,6 +407,8 @@ void ChatView::zoomIn()
     _currentScaleFactor *= 1.2;
     scale(1.2, 1.2);
     scene()->setWidth(viewport()->width() / _currentScaleFactor - 2);
+
+	setPageStep();
 }
 
 
@@ -402,6 +417,8 @@ void ChatView::zoomOut()
     _currentScaleFactor /= 1.2;
     scale(1 / 1.2, 1 / 1.2);
     scene()->setWidth(viewport()->width() / _currentScaleFactor - 2);
+
+	setPageStep();
 }
 
 
@@ -410,6 +427,8 @@ void ChatView::zoomOriginal()
     scale(1/_currentScaleFactor, 1/_currentScaleFactor);
     _currentScaleFactor = 1;
     scene()->setWidth(viewport()->width() - 2);
+
+	setPageStep();
 }
 
 
diff --git a/src/qtui/chatview.h b/src/qtui/chatview.h
index 8b50c55e..cf461103 100644
--- a/src/qtui/chatview.h
+++ b/src/qtui/chatview.h
@@ -96,6 +96,7 @@ protected:
 
 protected slots:
     virtual void verticalScrollbarChanged(int);
+	void setPageStep();
 
 private slots:
     void lastLineChanged(QGraphicsItem *chatLine, qreal offset);