diff --git a/app.lua b/app.lua
index 9552aef..6ed77f0 100644
--- a/app.lua
+++ b/app.lua
@@ -11,6 +11,7 @@
 --
 -- Scroll below this function for more details.
 function love.run()
+  App.version_check()
   App.snapshot_love()
   -- Tests always run at the start.
   Test_errors = {}
diff --git a/conf.lua b/conf.lua
deleted file mode 100644
index de8758a..0000000
--- a/conf.lua
+++ /dev/null
@@ -1,3 +0,0 @@
-function love.conf(t)
-  t.version = '11.4'
-end
diff --git a/main.lua b/main.lua
index b6d1bce..1e19a6c 100644
--- a/main.lua
+++ b/main.lua
@@ -13,6 +13,16 @@ require 'main_tests'
 require 'edit'
 Editor_state = {}
 
+function App.version_check()
+  Mode = 'version_check'
+  Supported_versions = {'11.4', '11.3', '11.2', '11.1', '11.0'}  -- keep these sorted in descending order
+  local major, minor = love.getVersion()
+  Version = major..'.'..minor
+  if array.find(Supported_versions, Version) then
+    Mode = 'run'
+  end
+end
+
 -- called both in tests and real run
 function App.initialize_globals()
   -- tests currently mostly clear their own state
@@ -154,10 +164,18 @@ function App.filedropped(file)
 end
 
 function App.draw()
+  if Mode == 'version_check' then
+    love.graphics.setColor(1,1,0)
+    love.graphics.rectangle('fill', 30,30, 400,400)
+    love.graphics.setColor(0,0,0)
+    love.graphics.printf(("This app doesn't support version %s; please use version %s. Press any key to try it with this version anyway."):format(Version, Supported_versions[1]), 40,40, 400)
+    return
+  end
   edit.draw(Editor_state)
 end
 
 function App.update(dt)
+  if Mode == 'version_check' then return end
   Current_time = Current_time + dt
   -- some hysteresis while resizing
   if Current_time < Last_resize_time + 0.1 then
@@ -168,6 +186,7 @@ function App.update(dt)
 end
 
 function love.quit()
+  if Mode == 'version_check' then return end
   edit.quit(Editor_state)
   -- save some important settings
   local x,y,displayindex = App.screen.position()
@@ -185,27 +204,32 @@ function love.quit()
 end
 
 function App.mousepressed(x,y, mouse_button)
+  if Mode == 'version_check' then return end
   Cursor_time = 0  -- ensure cursor is visible immediately after it moves
   return edit.mouse_press(Editor_state, x,y, mouse_button)
 end
 
 function App.mousereleased(x,y, mouse_button)
+  if Mode == 'version_check' then return end
   Cursor_time = 0  -- ensure cursor is visible immediately after it moves
   return edit.mouse_release(Editor_state, x,y, mouse_button)
 end
 
 function App.wheelmoved(dx,dy)
+  if Mode == 'version_check' then return end
   Cursor_time = 0  -- ensure cursor is visible immediately after it moves
   return edit.mouse_wheel_move(Editor_state, dx,dy)
 end
 
 function App.focus(in_focus)
+  if Mode == 'version_check' then return end
   if in_focus then
     Last_focus_time = Current_time
   end
 end
 
 function App.keychord_press(chord, key)
+  if Mode == 'version_check' then return end
   -- ignore events for some time after window in focus (mostly alt-tab)
   if Current_time < Last_focus_time + 0.01 then
     return
@@ -215,6 +239,7 @@ function App.keychord_press(chord, key)
 end
 
 function App.textinput(t)
+  if Mode == 'version_check' then return end
   -- ignore events for some time after window in focus (mostly alt-tab)
   if Current_time < Last_focus_time + 0.01 then
     return
@@ -224,6 +249,10 @@ function App.textinput(t)
 end
 
 function App.keyreleased(key, scancode)
+  if Mode == 'version_check' then
+    Mode = 'run'
+    return
+  end
   -- ignore events for some time after window in focus (mostly alt-tab)
   if Current_time < Last_focus_time + 0.01 then
     return