diff --git a/colors.js b/colors.js
index b981317..44ee612 100644
--- a/colors.js
+++ b/colors.js
@@ -48,7 +48,9 @@ var addProperty = function (color, func) {
   exports[color] = function (str) {
     return func.apply(str);
   };
-  String.prototype.__defineGetter__(color, func);
+  Object.defineProperty(String.prototype, color, {
+    get: func
+  });
 };
 
 
@@ -301,4 +303,4 @@ function zalgo(text, options) {
 // don't summon zalgo
 addProperty('zalgo', function () {
   return zalgo(this);
-});
\ No newline at end of file
+});