diff --git a/SketchWidget.py b/SketchWidget.py
index 3459852..cb7c170 100644
--- a/SketchWidget.py
+++ b/SketchWidget.py
@@ -215,6 +215,7 @@ class SketchWidget:
             self.view_center = (self.view_center[0] + this_pt[0] - start_pt[0],
                     self.view_center[1] + this_pt[1] - start_pt[1])
             self.panning_start = (event.x, event.y)
+            self.widget.queue_draw_area(0, 0, self.size[0], self.size[1])
 
     def scroll_event(self, widget, event, data = None):
         if event.direction == gtk.gdk.SCROLL_UP: