diff --git a/lib/grunt/file.js b/lib/grunt/file.js
index b039594e..a517fc0b 100644
--- a/lib/grunt/file.js
+++ b/lib/grunt/file.js
@@ -179,7 +179,7 @@ file.expandMapping = function(patterns, destBase, options) {
 file.mkdir = function(dirpath, mode) {
   if (grunt.option('no-write')) { return; }
   try {
-    fs.mkdirSync(dirpath, { recursive: true, mode })
+    fs.mkdirSync(dirpath, { recursive: true, mode: mode });
   } catch (e) {
     throw grunt.util.error('Unable to create directory "' + dirpath + '" (Error code: ' + e.code + ').', e);
   }