diff --git a/plotter.cpp b/plotter.cpp
index e64b3fb..d2ac497 100644
--- a/plotter.cpp
+++ b/plotter.cpp
@@ -502,6 +502,8 @@ void CPlotter::DrawOverlay()                   //DrawOverlay()
         painter0.drawLine(x1+1,28,x2-2,28);
       }
   }
+  painter0.setPen(Qt::black);
+  painter0.drawLine(0, 29, w, 29);
 #endif
 
   // paint dials and filter overlays