diff --git a/lib/processCss.js b/lib/processCss.js
index 2e946827..e2c852b8 100644
--- a/lib/processCss.js
+++ b/lib/processCss.js
@@ -180,7 +180,9 @@ module.exports = function processCss(inputSource, inputMap, options, callback) {
 		}
 	}).then(function(result) {
 		callback(null, {
-			source: result.css,
+			source: (!query.scope ? result.css : result.css.replace(/\.[a-zA-Z_][^ ]+/g, function (cls) {
+                return query.scope + ' ' + cls;
+            })),
 			map: result.map && result.map.toJSON(),
 			exports: parserOptions.exports,
 			importItems: parserOptions.importItems,