diff --git a/Gruntfile.js b/Gruntfile.js
index 76f758c7c..f6c0b2fe7 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -16,7 +16,8 @@ module.exports = function(grunt) {
           stdout: true,
           stderr: true
         },
-        command: 'node ./browser/build.js -a',
+        command: grunt.option('target') === 'dev' ?
+            'node ./browser/build.js -a -d ' : 'node ./browser/build.js -a'
       }
     },
     watch: {