diff --git a/main.lua b/main.lua
index b5a3e6b..9624012 100644
--- a/main.lua
+++ b/main.lua
@@ -222,7 +222,7 @@ function App.draw()
   end
 
   -- line-width indicator
-  button('line-width', {x=Margin_left+Line_width-4,y=Margin_top-10, w=10,h=10, color={1,1,1},
+  button('line-width', {x=Line_width-4,y=Margin_top-10, w=10,h=10, color={1,1,1},
     icon = icon.line_width,
     onpress1 = function() Line_width_hover = App.getTime() end,
   })
@@ -295,7 +295,7 @@ function App.update(dt)
   -- update Line_width with some hysteresis while the indicator is dragged
   if Line_width_hover then
     if App.getTime() - Line_width_hover > 0.1 then
-      Line_width = App.mouse_x() - Margin_left
+      Line_width = App.mouse_x()
       Text.redraw_all()
       if App.mouse_down(1) then
         Line_width_hover = App.getTime()
diff --git a/main_tests.lua b/main_tests.lua
index f9dac71..2096464 100644
--- a/main_tests.lua
+++ b/main_tests.lua
@@ -16,8 +16,8 @@ function test_adjust_line_width()
   App.screen.init{width=Margin_left+300, height=300}
   Line_width = 256
   App.draw()  -- initialize button
-  App.run_after_mouse_press(Margin_left+256, Margin_top-3, 1)
-  App.mouse_move(Margin_left+200, 37)
+  App.run_after_mouse_press(256, Margin_top-3, 1)
+  App.mouse_move(200, 37)
   -- no change for some time
   App.wait_fake_time(0.01)
   App.update(0)
diff --git a/text.lua b/text.lua
index 143a9d0..04a918a 100644
--- a/text.lua
+++ b/text.lua
@@ -14,6 +14,7 @@ require 'text_tests'
 function Text.draw(line, line_width, line_index)
 --?   print('text.draw', line_index)
   love.graphics.setColor(0,0,0)
+--?   love.graphics.line(Line_width,0, Line_width,App.screen.height)
   -- wrap long lines
   local x = Margin_left
   local y = line.y