diff --git a/gruntfile.js b/gruntfile.js
index 50881e8a..4e2e5849 100644
--- a/gruntfile.js
+++ b/gruntfile.js
@@ -286,7 +286,6 @@ module.exports = function (grunt) {
   })
 
   grunt.registerTask('bfm', function () {
-    const done = this.async()
     const root = path.join(__dirname, 'node_modules/codemirror/theme/')
 
     const colors = fs.readdirSync(root).map(file => {