diff --git a/js/main2e.js b/js/main2e.js
index 1ff5e48..089683d 100644
--- a/js/main2e.js
+++ b/js/main2e.js
@@ -769,7 +769,11 @@ function _keydown(evt) {
     } else if (evt.keyCode == 91 || evt.keyCode == 93) { // Command
         keyboard.commandKey(true);
     } else if (evt.keyCode == 18) { // Alt
-        keyboard.optionKey(true);
+        if (evt.originalEvent.location == 1) {
+            keyboard.commandKey(true);
+        } else {
+            keyboard.optionKey(true);
+        }
     }
 }
 
@@ -784,7 +788,11 @@ function _keyup(evt) {
     } else if (evt.keyCode == 91 || evt.keyCode == 93) { // Command
         keyboard.commandKey(false);
     } else if (evt.keyCode == 18) { // Alt
-        keyboard.optionKey(false);
+        if (evt.originalEvent.location == 1) {
+            keyboard.commandKey(false);
+        } else {
+            keyboard.optionKey(false);
+        }
     }
 }