diff --git a/index.js b/index.js
index ea949a41..89d1e6db 100755
--- a/index.js
+++ b/index.js
@@ -1,7 +1,7 @@
 /*jslint node: true */
 'use strict';
 
-var Promise = require('bluebird');
+var Promise = global.Promise || require('bluebird');
 var deprecate = require('util-deprecate');
 var sharp = require('./build/Release/sharp');