diff --git a/src/js/game/key_action_mapper.js b/src/js/game/key_action_mapper.js
index 7bacf6d4..ed681c90 100644
--- a/src/js/game/key_action_mapper.js
+++ b/src/js/game/key_action_mapper.js
@@ -262,7 +262,7 @@ export function getStringForKeyCode(code) {
             return "'";
     }
 
-    return code >= 65 && code <= 90 ? String.fromCharCode(code) : "�";
+    return 48 <= code && code <= 57 || 65 <= code && code <= 90 ? String.fromCharCode(code) : "[" + code + "]";
 }
 
 export class Keybinding {