| Index: lib/prefs.js | 
| =================================================================== | 
| --- a/lib/prefs.js | 
| +++ b/lib/prefs.js | 
| @@ -52,20 +52,24 @@ | 
|  | 
| function defineProperty(key) | 
| { | 
| -  Prefs.__defineGetter__(key, function() values[key]); | 
| -  Prefs.__defineSetter__(key, function(value) | 
| +  Object.defineProperty(Prefs, key, | 
| { | 
| -    if (typeof value != typeof defaults[key]) | 
| -      throw new Error("Attempt to change preference type"); | 
| +    get: () => values[key], | 
| +    set: function(value) | 
| +    { | 
| +      if (typeof value != typeof defaults[key]) | 
| +        throw new Error("Attempt to change preference type"); | 
|  | 
| -    if (value == defaults[key]) | 
| -      delete values[key]; | 
| -    else | 
| -      values[key] = value; | 
| -    save(); | 
| +      if (value == defaults[key]) | 
| +        delete values[key]; | 
| +      else | 
| +        values[key] = value; | 
| +      save(); | 
|  | 
| -    for (let listener of listeners) | 
| -      listener(key); | 
| +      for (let listener of listeners) | 
| +        listener(key); | 
| +    }, | 
| +    enumerable: true | 
| }); | 
| } | 
|  | 
|  |