diff --git a/lib/less/source-map-output.js b/lib/less/source-map-output.js
index aeddd333..5d7d6a87 100644
--- a/lib/less/source-map-output.js
+++ b/lib/less/source-map-output.js
@@ -127,7 +127,7 @@ module.exports = function (less) {
             if (this._writeSourceMap) {
                 this._writeSourceMap(sourceMapContent);
             } else {
-                sourceMapURL = "data:application/json;base64," + require('./encoder.js').encodeBase64(sourceMapContent);
+                sourceMapURL = "data:application/json;base64," + less.environment.encodeBase64(sourceMapContent);
             }
 
             if (sourceMapURL) {