diff --git a/main.js b/main.js
index 9e7bfe8..fc273ca 100644
--- a/main.js
+++ b/main.js
@@ -8,6 +8,10 @@ const Orientation = {
   RIGHT: 'right'
 }
 
+function bound(low, x, high) {
+  return Math.max(low, Math.min(x, high));
+}
+
 class Input {
   constructor() {
     this.up = false;
@@ -524,7 +528,7 @@ function setCanvasScale(scale) {
 function setAutoCanvasScale() {
   const widthAspect = Math.floor(window.innerWidth / SNES_WIDTH);
   const heightAspect = Math.floor(window.innerHeight / SNES_HEIGHT);
-  const scale = Math.min(widthAspect, heightAspect)
+  const scale = bound(1, Math.min(widthAspect, heightAspect), 8);
   setCanvasScale(scale);
 }