diff --git a/client/grunt-tasks/style.js b/client/grunt-tasks/style.js
index fc716e04a2a..190d2722f89 100644
--- a/client/grunt-tasks/style.js
+++ b/client/grunt-tasks/style.js
@@ -67,6 +67,9 @@ module.exports = function( grunt ){
 
     // remove tmp files
     grunt.config( 'clean', {
+        options : {
+            force: true
+        },
         clean : [
             fmt( '%s/tmp-site-config.less', lessPath )
         ]