diff --git a/lib/compiless.js b/lib/compiless.js
index <HASH>..<HASH> 100644
--- a/lib/compiless.js
+++ b/lib/compiless.js
@@ -3,8 +3,7 @@ var Path = require('path'),
     fs = require('fs'),
     async = require('async'),
     _ = require('underscore'),
-    passError = require('passerror'),
-    less = require('less');
+    passError = require('passerror');
 
 require('express-hijackresponse');
 require('bufferjs');
@@ -27,6 +26,7 @@ module.exports = function compiless(options) {
     if (!options || !options.root) {
         throw new Error('options.root is mandatory');
     }
+    var less = options.less || require('less');
     return function (req, res, next) {
         if ((req.headers.accept && req.accepts('text/css')) || /\.less(?:\?.*)?$/.test(req.url)) {
             // Prevent If-None-Match revalidation with the downstream middleware with ETags that aren't suffixed with "-compiless":
Made the 'less' module a config option so that the caller can choose to up- or downgrade the bundled version.