diff --git a/app.lua b/app.lua
index ddc175d..9bf5e6a 100644
--- a/app.lua
+++ b/app.lua
@@ -207,22 +207,22 @@ function App.modifier_down(key)
 end
 
 App.fake_mouse_state = {x=-1, y=-1}  -- x,y always set
-function App.fake_mouse_press(x,y, button)
+function App.fake_mouse_press(x,y, mouse_button)
   App.fake_mouse_state.x = x
   App.fake_mouse_state.y = y
-  App.fake_mouse_state[button] = true
+  App.fake_mouse_state[mouse_button] = true
 end
-function App.fake_mouse_release(x,y, button)
+function App.fake_mouse_release(x,y, mouse_button)
   App.fake_mouse_state.x = x
   App.fake_mouse_state.y = y
-  App.fake_mouse_state[button] = nil
+  App.fake_mouse_state[mouse_button] = nil
 end
 function App.mouse_move(x,y)
   App.fake_mouse_state.x = x
   App.fake_mouse_state.y = y
 end
-function App.mouse_down(button)
-  return App.fake_mouse_state[button]
+function App.mouse_down(mouse_button)
+  return App.fake_mouse_state[mouse_button]
 end
 function App.mouse_x()
   return App.fake_mouse_state.x
@@ -250,25 +250,25 @@ function App.run_after_keychord(chord)
   App.draw()
 end
 
-function App.run_after_mouse_click(x,y, button)
-  App.fake_mouse_press(x,y, button)
-  App.mousepressed(x,y, button)
-  App.fake_mouse_release(x,y, button)
-  App.mousereleased(x,y, button)
+function App.run_after_mouse_click(x,y, mouse_button)
+  App.fake_mouse_press(x,y, mouse_button)
+  App.mousepressed(x,y, mouse_button)
+  App.fake_mouse_release(x,y, mouse_button)
+  App.mousereleased(x,y, mouse_button)
   App.screen.contents = {}
   App.draw()
 end
 
-function App.run_after_mouse_press(x,y, button)
-  App.fake_mouse_press(x,y, button)
-  App.mousepressed(x,y, button)
+function App.run_after_mouse_press(x,y, mouse_button)
+  App.fake_mouse_press(x,y, mouse_button)
+  App.mousepressed(x,y, mouse_button)
   App.screen.contents = {}
   App.draw()
 end
 
-function App.run_after_mouse_release(x,y, button)
-  App.fake_mouse_release(x,y, button)
-  App.mousereleased(x,y, button)
+function App.run_after_mouse_release(x,y, mouse_button)
+  App.fake_mouse_release(x,y, mouse_button)
+  App.mousereleased(x,y, mouse_button)
   App.screen.contents = {}
   App.draw()
 end
diff --git a/drawing.lua b/drawing.lua
index 8263dd9..26683b2 100644
--- a/drawing.lua
+++ b/drawing.lua
@@ -218,7 +218,7 @@ function Drawing.in_drawing(drawing, line_cache, x,y, left,right)
   return y >= line_cache.starty and y < line_cache.starty + Drawing.pixels(drawing.h, width) and x >= left and x < right
 end
 
-function Drawing.mouse_pressed(State, drawing_index, x,y, button)
+function Drawing.mouse_pressed(State, drawing_index, x,y, mouse_button)
   local drawing = State.lines[drawing_index]
   local line_cache = State.line_cache[drawing_index]
   local cx = Drawing.coord(x-State.left, State.width)
@@ -292,7 +292,7 @@ function Drawing.relax_constraints(drawing, p)
   end
 end
 
-function Drawing.mouse_released(State, x,y, button)
+function Drawing.mouse_released(State, x,y, mouse_button)
   if State.current_drawing_mode == 'move' then
     State.current_drawing_mode = State.previous_drawing_mode
     State.previous_drawing_mode = nil
diff --git a/edit.lua b/edit.lua
index 011f6b9..9a7674d 100644
--- a/edit.lua
+++ b/edit.lua
@@ -497,25 +497,25 @@ function edit.run_after_keychord(State, chord)
   edit.draw(State)
 end
 
-function edit.run_after_mouse_click(State, x,y, button)
-  App.fake_mouse_press(x,y, button)
-  edit.mouse_pressed(State, x,y, button)
-  App.fake_mouse_release(x,y, button)
-  edit.mouse_released(State, x,y, button)
+function edit.run_after_mouse_click(State, x,y, mouse_button)
+  App.fake_mouse_press(x,y, mouse_button)
+  edit.mouse_pressed(State, x,y, mouse_button)
+  App.fake_mouse_release(x,y, mouse_button)
+  edit.mouse_released(State, x,y, mouse_button)
   App.screen.contents = {}
   edit.draw(State)
 end
 
-function edit.run_after_mouse_press(State, x,y, button)
-  App.fake_mouse_press(x,y, button)
-  edit.mouse_pressed(State, x,y, button)
+function edit.run_after_mouse_press(State, x,y, mouse_button)
+  App.fake_mouse_press(x,y, mouse_button)
+  edit.mouse_pressed(State, x,y, mouse_button)
   App.screen.contents = {}
   edit.draw(State)
 end
 
-function edit.run_after_mouse_release(State, x,y, button)
-  App.fake_mouse_release(x,y, button)
-  edit.mouse_released(State, x,y, button)
+function edit.run_after_mouse_release(State, x,y, mouse_button)
+  App.fake_mouse_release(x,y, mouse_button)
+  edit.mouse_released(State, x,y, mouse_button)
   App.screen.contents = {}
   edit.draw(State)
 end