diff --git a/plot.c b/plot.c
index 170caa7..0538340 100644
--- a/plot.c
+++ b/plot.c
@@ -149,6 +149,8 @@ void update_grid(void)
   grid_width = (WIDTH) * (grid / 100) / (fspan / 1000);
 
   force_set_markmap();
+  if (get_waterfall())
+    ili9341_fill(OFFSETX, graph_bottom, LCD_WIDTH - OFFSETX, CHART_BOTTOM - graph_bottom, 0);
   redraw_request |= REDRAW_FREQUENCY;
 }
 
diff --git a/ui.c b/ui.c
index 3c32ad9..7b5be97 100644
--- a/ui.c
+++ b/ui.c
@@ -1928,6 +1928,8 @@ leave_ui_mode()
   // Erase bottom area (not redraw on area update)
   if (MENU_BUTTON_HEIGHT*MENU_BUTTON_MAX - area_height > 0)
     ili9341_fill(LCD_WIDTH-MENU_BUTTON_WIDTH, area_height, MENU_BUTTON_WIDTH, MENU_BUTTON_HEIGHT*MENU_BUTTON_MAX - area_height, DEFAULT_BG_COLOR);
+  if (get_waterfall())
+    ili9341_fill(OFFSETX, graph_bottom, LCD_WIDTH - OFFSETX, CHART_BOTTOM - graph_bottom, 0);
   redraw_request|=REDRAW_AREA | REDRAW_FREQUENCY | REDRAW_CAL_STATUS | REDRAW_BATTERY;
 }