diff --git a/Gruntfile.js b/Gruntfile.js
index b4541e17b6405f3972734e8353d9f35db0c070e4..994a5008713bfec740782484c91adae8c668e3ed 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -321,7 +321,7 @@ module.exports = function (grunt) {
           conservativeCollapse: true,
           decodeEntities: false,
           minifyCSS: {
-            compatibility: "ie8",
+            compatibility: 'ie8',
             keepSpecialComments: 0
           },
           minifyJS: true,