diff --git a/data/main.lua b/data/main.lua
index 399334a..ac30079 100644
--- a/data/main.lua
+++ b/data/main.lua
@@ -80,10 +80,10 @@ function _init()
 end
 
 function _update()
-    if btnp(KEY_F2) then
-        local val = zoom() + 2
-        if val >= 10 then val = 2 end
-        zoom(val)
+    if btnp(KEY_F1) then
+        zoom(zoom()-1)
+    elseif btnp(KEY_F2) then
+        zoom(zoom()+1)
     elseif btnp(KEY_F3) then
         local fs = fullscreen()
         fullscreen(not fs)